Text file src/cmd/compile/internal/ssa/_gen/RISCV64.rules

     1  // Copyright 2016 The Go Authors. All rights reserved.
     2  // Use of this source code is governed by a BSD-style
     3  // license that can be found in the LICENSE file.
     4  
     5  // Lowering arithmetic
     6  (Add(Ptr|64|32|16|8) ...) => (ADD ...)
     7  (Add(64|32)F ...) => (FADD(D|S) ...)
     8  
     9  (Sub(Ptr|64|32|16|8) ...) => (SUB ...)
    10  (Sub(64|32)F ...) => (FSUB(D|S) ...)
    11  
    12  (Mul64 ...) => (MUL  ...)
    13  (Mul64uhilo ...) => (LoweredMuluhilo ...)
    14  (Mul64uover ...) => (LoweredMuluover ...)
    15  (Mul32 ...) => (MULW ...)
    16  (Mul16 x y) => (MULW (SignExt16to32 x) (SignExt16to32 y))
    17  (Mul8 x y)  => (MULW (SignExt8to32 x)  (SignExt8to32 y))
    18  (Mul(64|32)F ...) => (FMUL(D|S) ...)
    19  
    20  (Div(64|32)F ...) => (FDIV(D|S) ...)
    21  
    22  (Div64 x y [false])  => (DIV x y)
    23  (Div64u ...) => (DIVU ...)
    24  (Div32 x y [false])  => (DIVW x y)
    25  (Div32u ...) => (DIVUW ...)
    26  (Div16 x y [false])  => (DIVW  (SignExt16to32 x) (SignExt16to32 y))
    27  (Div16u x y) => (DIVUW (ZeroExt16to32 x) (ZeroExt16to32 y))
    28  (Div8 x y)   => (DIVW  (SignExt8to32 x)  (SignExt8to32 y))
    29  (Div8u x y)  => (DIVUW (ZeroExt8to32 x)  (ZeroExt8to32 y))
    30  
    31  (Hmul64 ...)  => (MULH  ...)
    32  (Hmul64u ...) => (MULHU ...)
    33  (Hmul32 x y)  => (SRAI [32] (MUL  (SignExt32to64 x) (SignExt32to64 y)))
    34  (Hmul32u x y) => (SRLI [32] (MUL  (ZeroExt32to64 x) (ZeroExt32to64 y)))
    35  
    36  (Select0 (Add64carry x y c)) => (ADD (ADD <typ.UInt64> x y) c)
    37  (Select1 (Add64carry x y c)) =>
    38  	(OR (SLTU <typ.UInt64> s:(ADD <typ.UInt64> x y) x) (SLTU <typ.UInt64> (ADD <typ.UInt64> s c) s))
    39  
    40  (Select0 (Sub64borrow x y c)) => (SUB (SUB <typ.UInt64> x y) c)
    41  (Select1 (Sub64borrow x y c)) =>
    42  	(OR (SLTU <typ.UInt64> x s:(SUB <typ.UInt64> x y)) (SLTU <typ.UInt64> s (SUB <typ.UInt64> s c)))
    43  
    44  // (x + y) / 2 => (x / 2) + (y / 2) + (x & y & 1)
    45  (Avg64u <t> x y) => (ADD (ADD <t> (SRLI <t> [1] x) (SRLI <t> [1] y)) (ANDI <t> [1] (AND <t> x y)))
    46  
    47  (Mod64 x y [false])  => (REM x y)
    48  (Mod64u ...) => (REMU  ...)
    49  (Mod32 x y [false])  => (REMW x y)
    50  (Mod32u ...) => (REMUW ...)
    51  (Mod16 x y [false])  => (REMW  (SignExt16to32 x) (SignExt16to32 y))
    52  (Mod16u x y) => (REMUW (ZeroExt16to32 x) (ZeroExt16to32 y))
    53  (Mod8 x y)   => (REMW  (SignExt8to32  x) (SignExt8to32  y))
    54  (Mod8u x y)  => (REMUW (ZeroExt8to32  x) (ZeroExt8to32  y))
    55  
    56  (And(64|32|16|8) ...) => (AND ...)
    57  (Or(64|32|16|8) ...) => (OR ...)
    58  (Xor(64|32|16|8) ...) => (XOR ...)
    59  
    60  (Neg(64|32|16|8) ...) => (NEG ...)
    61  (Neg(64|32)F ...) => (FNEG(D|S) ...)
    62  
    63  (Com(64|32|16|8) ...) => (NOT ...)
    64  
    65  (Sqrt ...) => (FSQRTD ...)
    66  (Sqrt32 ...) => (FSQRTS ...)
    67  
    68  (Copysign ...) => (FSGNJD ...)
    69  
    70  (Abs ...) => (FABSD ...)
    71  
    72  (FMA ...) => (FMADDD ...)
    73  
    74  (Min(64|32)F ...) => (LoweredFMIN(D|S) ...)
    75  (Max(64|32)F ...) => (LoweredFMAX(D|S) ...)
    76  
    77  // Sign and zero extension.
    78  
    79  (SignExt8to16  ...) => (MOVBreg ...)
    80  (SignExt8to32  ...) => (MOVBreg ...)
    81  (SignExt8to64  ...) => (MOVBreg ...)
    82  (SignExt16to32 ...) => (MOVHreg ...)
    83  (SignExt16to64 ...) => (MOVHreg ...)
    84  (SignExt32to64 ...) => (MOVWreg ...)
    85  
    86  (ZeroExt8to16  ...) => (MOVBUreg ...)
    87  (ZeroExt8to32  ...) => (MOVBUreg ...)
    88  (ZeroExt8to64  ...) => (MOVBUreg ...)
    89  (ZeroExt16to32 ...) => (MOVHUreg ...)
    90  (ZeroExt16to64 ...) => (MOVHUreg ...)
    91  (ZeroExt32to64 ...) => (MOVWUreg ...)
    92  
    93  (Cvt32to32F ...) => (FCVTSW ...)
    94  (Cvt32to64F ...) => (FCVTDW ...)
    95  (Cvt64to32F ...) => (FCVTSL ...)
    96  (Cvt64to64F ...) => (FCVTDL ...)
    97  
    98  (Cvt32Fto32 ...) => (FCVTWS ...)
    99  (Cvt32Fto64 ...) => (FCVTLS ...)
   100  (Cvt64Fto32 ...) => (FCVTWD ...)
   101  (Cvt64Fto64 ...) => (FCVTLD ...)
   102  
   103  (Cvt32Fto64F ...) => (FCVTDS ...)
   104  (Cvt64Fto32F ...) => (FCVTSD ...)
   105  
   106  (CvtBoolToUint8 ...) => (Copy ...)
   107  
   108  (Round(32|64)F ...) => (LoweredRound(32|64)F ...)
   109  
   110  (Slicemask <t> x) => (SRAI [63] (NEG <t> x))
   111  
   112  // Truncations
   113  // We ignore the unused high parts of registers, so truncates are just copies.
   114  (Trunc16to8  ...) => (Copy ...)
   115  (Trunc32to8  ...) => (Copy ...)
   116  (Trunc32to16 ...) => (Copy ...)
   117  (Trunc64to8  ...) => (Copy ...)
   118  (Trunc64to16 ...) => (Copy ...)
   119  (Trunc64to32 ...) => (Copy ...)
   120  
   121  // Shifts
   122  
   123  // SLL only considers the bottom 6 bits of y. If y > 64, the result should
   124  // always be 0.
   125  //
   126  // Breaking down the operation:
   127  //
   128  // (SLL x y) generates x << (y & 63).
   129  //
   130  // If y < 64, this is the value we want. Otherwise, we want zero.
   131  //
   132  // So, we AND with -1 * uint64(y < 64), which is 0xfffff... if y < 64 and 0 otherwise.
   133  (Lsh8x8   <t> x y) && !shiftIsBounded(v) => (AND (SLL <t> x y) (Neg8  <t> (SLTIU <t> [64] (ZeroExt8to64  y))))
   134  (Lsh8x16  <t> x y) && !shiftIsBounded(v) => (AND (SLL <t> x y) (Neg8  <t> (SLTIU <t> [64] (ZeroExt16to64 y))))
   135  (Lsh8x32  <t> x y) && !shiftIsBounded(v) => (AND (SLL <t> x y) (Neg8  <t> (SLTIU <t> [64] (ZeroExt32to64 y))))
   136  (Lsh8x64  <t> x y) && !shiftIsBounded(v) => (AND (SLL <t> x y) (Neg8  <t> (SLTIU <t> [64] y)))
   137  (Lsh16x8  <t> x y) && !shiftIsBounded(v) => (AND (SLL <t> x y) (Neg16 <t> (SLTIU <t> [64] (ZeroExt8to64  y))))
   138  (Lsh16x16 <t> x y) && !shiftIsBounded(v) => (AND (SLL <t> x y) (Neg16 <t> (SLTIU <t> [64] (ZeroExt16to64 y))))
   139  (Lsh16x32 <t> x y) && !shiftIsBounded(v) => (AND (SLL <t> x y) (Neg16 <t> (SLTIU <t> [64] (ZeroExt32to64 y))))
   140  (Lsh16x64 <t> x y) && !shiftIsBounded(v) => (AND (SLL <t> x y) (Neg16 <t> (SLTIU <t> [64] y)))
   141  (Lsh32x8  <t> x y) && !shiftIsBounded(v) => (AND (SLL <t> x y) (Neg32 <t> (SLTIU <t> [64] (ZeroExt8to64  y))))
   142  (Lsh32x16 <t> x y) && !shiftIsBounded(v) => (AND (SLL <t> x y) (Neg32 <t> (SLTIU <t> [64] (ZeroExt16to64 y))))
   143  (Lsh32x32 <t> x y) && !shiftIsBounded(v) => (AND (SLL <t> x y) (Neg32 <t> (SLTIU <t> [64] (ZeroExt32to64 y))))
   144  (Lsh32x64 <t> x y) && !shiftIsBounded(v) => (AND (SLL <t> x y) (Neg32 <t> (SLTIU <t> [64] y)))
   145  (Lsh64x8  <t> x y) && !shiftIsBounded(v) => (AND (SLL <t> x y) (Neg64 <t> (SLTIU <t> [64] (ZeroExt8to64  y))))
   146  (Lsh64x16 <t> x y) && !shiftIsBounded(v) => (AND (SLL <t> x y) (Neg64 <t> (SLTIU <t> [64] (ZeroExt16to64 y))))
   147  (Lsh64x32 <t> x y) && !shiftIsBounded(v) => (AND (SLL <t> x y) (Neg64 <t> (SLTIU <t> [64] (ZeroExt32to64 y))))
   148  (Lsh64x64 <t> x y) && !shiftIsBounded(v) => (AND (SLL <t> x y) (Neg64 <t> (SLTIU <t> [64] y)))
   149  
   150  (Lsh8x(64|32|16|8)  x y) && shiftIsBounded(v) => (SLL x y)
   151  (Lsh16x(64|32|16|8) x y) && shiftIsBounded(v) => (SLL x y)
   152  (Lsh32x(64|32|16|8) x y) && shiftIsBounded(v) => (SLL x y)
   153  (Lsh64x(64|32|16|8) x y) && shiftIsBounded(v) => (SLL x y)
   154  
   155  // SRL only considers the bottom 6 bits of y, similarly SRLW only considers the
   156  // bottom 5 bits of y. Ensure that the result is always zero if the shift exceeds
   157  // the maximum value. See Lsh above for a detailed description.
   158  (Rsh8Ux8   <t> x y) && !shiftIsBounded(v) => (AND (SRL  <t> (ZeroExt8to64  x) y) (Neg8  <t> (SLTIU <t> [64] (ZeroExt8to64  y))))
   159  (Rsh8Ux16  <t> x y) && !shiftIsBounded(v) => (AND (SRL  <t> (ZeroExt8to64  x) y) (Neg8  <t> (SLTIU <t> [64] (ZeroExt16to64 y))))
   160  (Rsh8Ux32  <t> x y) && !shiftIsBounded(v) => (AND (SRL  <t> (ZeroExt8to64  x) y) (Neg8  <t> (SLTIU <t> [64] (ZeroExt32to64 y))))
   161  (Rsh8Ux64  <t> x y) && !shiftIsBounded(v) => (AND (SRL  <t> (ZeroExt8to64  x) y) (Neg8  <t> (SLTIU <t> [64] y)))
   162  (Rsh16Ux8  <t> x y) && !shiftIsBounded(v) => (AND (SRL  <t> (ZeroExt16to64 x) y) (Neg16 <t> (SLTIU <t> [64] (ZeroExt8to64  y))))
   163  (Rsh16Ux16 <t> x y) && !shiftIsBounded(v) => (AND (SRL  <t> (ZeroExt16to64 x) y) (Neg16 <t> (SLTIU <t> [64] (ZeroExt16to64 y))))
   164  (Rsh16Ux32 <t> x y) && !shiftIsBounded(v) => (AND (SRL  <t> (ZeroExt16to64 x) y) (Neg16 <t> (SLTIU <t> [64] (ZeroExt32to64 y))))
   165  (Rsh16Ux64 <t> x y) && !shiftIsBounded(v) => (AND (SRL  <t> (ZeroExt16to64 x) y) (Neg16 <t> (SLTIU <t> [64] y)))
   166  (Rsh32Ux8  <t> x y) && !shiftIsBounded(v) => (AND (SRLW <t>  x                y) (Neg32 <t> (SLTIU <t> [32] (ZeroExt8to64  y))))
   167  (Rsh32Ux16 <t> x y) && !shiftIsBounded(v) => (AND (SRLW <t>  x                y) (Neg32 <t> (SLTIU <t> [32] (ZeroExt16to64 y))))
   168  (Rsh32Ux32 <t> x y) && !shiftIsBounded(v) => (AND (SRLW <t>  x                y) (Neg32 <t> (SLTIU <t> [32] (ZeroExt32to64 y))))
   169  (Rsh32Ux64 <t> x y) && !shiftIsBounded(v) => (AND (SRLW <t>  x                y) (Neg32 <t> (SLTIU <t> [32] y)))
   170  (Rsh64Ux8  <t> x y) && !shiftIsBounded(v) => (AND (SRL  <t>  x                y) (Neg64 <t> (SLTIU <t> [64] (ZeroExt8to64  y))))
   171  (Rsh64Ux16 <t> x y) && !shiftIsBounded(v) => (AND (SRL  <t>  x                y) (Neg64 <t> (SLTIU <t> [64] (ZeroExt16to64 y))))
   172  (Rsh64Ux32 <t> x y) && !shiftIsBounded(v) => (AND (SRL  <t>  x                y) (Neg64 <t> (SLTIU <t> [64] (ZeroExt32to64 y))))
   173  (Rsh64Ux64 <t> x y) && !shiftIsBounded(v) => (AND (SRL  <t>  x                y) (Neg64 <t> (SLTIU <t> [64] y)))
   174  
   175  (Rsh8Ux(64|32|16|8)  x y) && shiftIsBounded(v) => (SRL  (ZeroExt8to64  x) y)
   176  (Rsh16Ux(64|32|16|8) x y) && shiftIsBounded(v) => (SRL  (ZeroExt16to64 x) y)
   177  (Rsh32Ux(64|32|16|8) x y) && shiftIsBounded(v) => (SRLW x                 y)
   178  (Rsh64Ux(64|32|16|8) x y) && shiftIsBounded(v) => (SRL  x                 y)
   179  
   180  // SRA only considers the bottom 6 bits of y, similarly SRAW only considers the
   181  // bottom 5 bits. If y is greater than the maximum value (either 63 or 31
   182  // depending on the instruction),  the result of the shift should be either 0
   183  // or -1 based on the sign bit of x.
   184  //
   185  // We implement this by performing the max shift (-1) if y > the maximum value.
   186  //
   187  // We OR (uint64(y < 64) - 1) into y before passing it to SRA. This leaves
   188  // us with -1 (0xffff...) if y >= 64.  Similarly, we OR (uint64(y < 32) - 1) into y
   189  // before passing it to SRAW.
   190  //
   191  // We don't need to sign-extend the OR result, as it will be at minimum 8 bits,
   192  // more than the 5 or 6 bits SRAW and SRA care about.
   193  (Rsh8x8   <t> x y) && !shiftIsBounded(v) => (SRA  <t> (SignExt8to64  x) (OR <y.Type> y (ADDI <y.Type> [-1] (SLTIU <y.Type> [64] (ZeroExt8to64  y)))))
   194  (Rsh8x16  <t> x y) && !shiftIsBounded(v) => (SRA  <t> (SignExt8to64  x) (OR <y.Type> y (ADDI <y.Type> [-1] (SLTIU <y.Type> [64] (ZeroExt16to64 y)))))
   195  (Rsh8x32  <t> x y) && !shiftIsBounded(v) => (SRA  <t> (SignExt8to64  x) (OR <y.Type> y (ADDI <y.Type> [-1] (SLTIU <y.Type> [64] (ZeroExt32to64 y)))))
   196  (Rsh8x64  <t> x y) && !shiftIsBounded(v) => (SRA  <t> (SignExt8to64  x) (OR <y.Type> y (ADDI <y.Type> [-1] (SLTIU <y.Type> [64] y))))
   197  (Rsh16x8  <t> x y) && !shiftIsBounded(v) => (SRA  <t> (SignExt16to64 x) (OR <y.Type> y (ADDI <y.Type> [-1] (SLTIU <y.Type> [64] (ZeroExt8to64  y)))))
   198  (Rsh16x16 <t> x y) && !shiftIsBounded(v) => (SRA  <t> (SignExt16to64 x) (OR <y.Type> y (ADDI <y.Type> [-1] (SLTIU <y.Type> [64] (ZeroExt16to64 y)))))
   199  (Rsh16x32 <t> x y) && !shiftIsBounded(v) => (SRA  <t> (SignExt16to64 x) (OR <y.Type> y (ADDI <y.Type> [-1] (SLTIU <y.Type> [64] (ZeroExt32to64 y)))))
   200  (Rsh16x64 <t> x y) && !shiftIsBounded(v) => (SRA  <t> (SignExt16to64 x) (OR <y.Type> y (ADDI <y.Type> [-1] (SLTIU <y.Type> [64] y))))
   201  (Rsh32x8  <t> x y) && !shiftIsBounded(v) => (SRAW <t> x                 (OR <y.Type> y (ADDI <y.Type> [-1] (SLTIU <y.Type> [32] (ZeroExt8to64  y)))))
   202  (Rsh32x16 <t> x y) && !shiftIsBounded(v) => (SRAW <t> x                 (OR <y.Type> y (ADDI <y.Type> [-1] (SLTIU <y.Type> [32] (ZeroExt16to64 y)))))
   203  (Rsh32x32 <t> x y) && !shiftIsBounded(v) => (SRAW <t> x                 (OR <y.Type> y (ADDI <y.Type> [-1] (SLTIU <y.Type> [32] (ZeroExt32to64 y)))))
   204  (Rsh32x64 <t> x y) && !shiftIsBounded(v) => (SRAW <t> x                 (OR <y.Type> y (ADDI <y.Type> [-1] (SLTIU <y.Type> [32] y))))
   205  (Rsh64x8  <t> x y) && !shiftIsBounded(v) => (SRA  <t> x                 (OR <y.Type> y (ADDI <y.Type> [-1] (SLTIU <y.Type> [64] (ZeroExt8to64  y)))))
   206  (Rsh64x16 <t> x y) && !shiftIsBounded(v) => (SRA  <t> x                 (OR <y.Type> y (ADDI <y.Type> [-1] (SLTIU <y.Type> [64] (ZeroExt16to64 y)))))
   207  (Rsh64x32 <t> x y) && !shiftIsBounded(v) => (SRA  <t> x                 (OR <y.Type> y (ADDI <y.Type> [-1] (SLTIU <y.Type> [64] (ZeroExt32to64 y)))))
   208  (Rsh64x64 <t> x y) && !shiftIsBounded(v) => (SRA  <t> x                 (OR <y.Type> y (ADDI <y.Type> [-1] (SLTIU <y.Type> [64] y))))
   209  
   210  (Rsh8x(64|32|16|8)  x y) && shiftIsBounded(v) => (SRA  (SignExt8to64  x) y)
   211  (Rsh16x(64|32|16|8) x y) && shiftIsBounded(v) => (SRA  (SignExt16to64 x) y)
   212  (Rsh32x(64|32|16|8) x y) && shiftIsBounded(v) => (SRAW  x                y)
   213  (Rsh64x(64|32|16|8) x y) && shiftIsBounded(v) => (SRA   x                y)
   214  
   215  // Rotates.
   216  (RotateLeft8  <t> x y) => (OR (SLL  <t> x (ANDI [7]  <y.Type> y)) (SRL <t> (ZeroExt8to64  x) (ANDI [7]  <y.Type> (NEG <y.Type> y))))
   217  (RotateLeft16 <t> x y) => (OR (SLL  <t> x (ANDI [15] <y.Type> y)) (SRL <t> (ZeroExt16to64 x) (ANDI [15] <y.Type> (NEG <y.Type> y))))
   218  (RotateLeft32 ...) => (ROLW ...)
   219  (RotateLeft64 ...) => (ROL  ...)
   220  
   221  (Less64  ...) => (SLT  ...)
   222  (Less32  x y) => (SLT  (SignExt32to64 x) (SignExt32to64 y))
   223  (Less16  x y) => (SLT  (SignExt16to64 x) (SignExt16to64 y))
   224  (Less8   x y) => (SLT  (SignExt8to64  x) (SignExt8to64  y))
   225  (Less64U ...) => (SLTU ...)
   226  (Less32U x y) => (SLTU (ZeroExt32to64 x) (ZeroExt32to64 y))
   227  (Less16U x y) => (SLTU (ZeroExt16to64 x) (ZeroExt16to64 y))
   228  (Less8U  x y) => (SLTU (ZeroExt8to64  x) (ZeroExt8to64  y))
   229  (Less(64|32)F ...) => (FLT(D|S) ...)
   230  
   231  // Convert x <= y to !(y > x).
   232  (Leq(64|32|16|8)  x y) => (Not (Less(64|32|16|8)  y x))
   233  (Leq(64|32|16|8)U x y) => (Not (Less(64|32|16|8)U y x))
   234  (Leq(64|32)F ...) => (FLE(D|S) ...)
   235  
   236  (EqPtr x y) => (SEQZ (SUB <typ.Uintptr> x y))
   237  (Eq64  x y) => (SEQZ (SUB <x.Type> x y))
   238  (Eq32  x y) &&  x.Type.IsSigned() => (SEQZ (SUB <x.Type> (SignExt32to64 x) (SignExt32to64 y)))
   239  (Eq32  x y) && !x.Type.IsSigned() => (SEQZ (SUB <x.Type> (ZeroExt32to64 x) (ZeroExt32to64 y)))
   240  (Eq16  x y) => (SEQZ (SUB <x.Type> (ZeroExt16to64 x) (ZeroExt16to64 y)))
   241  (Eq8   x y) => (SEQZ (SUB <x.Type> (ZeroExt8to64  x) (ZeroExt8to64  y)))
   242  (Eq(64|32)F ...) => (FEQ(D|S) ...)
   243  
   244  (NeqPtr x y) => (Not (EqPtr x y))
   245  (Neq64  x y) => (Not (Eq64  x y))
   246  (Neq32  x y) => (Not (Eq32  x y))
   247  (Neq16  x y) => (Not (Eq16  x y))
   248  (Neq8   x y) => (Not (Eq8   x y))
   249  (Neq(64|32)F ...) => (FNE(D|S) ...)
   250  
   251  // Loads
   252  (Load <t> ptr mem) &&  t.IsBoolean()                   => (MOVBUload ptr mem)
   253  (Load <t> ptr mem) && ( is8BitInt(t) &&  t.IsSigned()) => (MOVBload  ptr mem)
   254  (Load <t> ptr mem) && ( is8BitInt(t) && !t.IsSigned()) => (MOVBUload ptr mem)
   255  (Load <t> ptr mem) && (is16BitInt(t) &&  t.IsSigned()) => (MOVHload  ptr mem)
   256  (Load <t> ptr mem) && (is16BitInt(t) && !t.IsSigned()) => (MOVHUload ptr mem)
   257  (Load <t> ptr mem) && (is32BitInt(t) &&  t.IsSigned()) => (MOVWload  ptr mem)
   258  (Load <t> ptr mem) && (is32BitInt(t) && !t.IsSigned()) => (MOVWUload ptr mem)
   259  (Load <t> ptr mem) && (is64BitInt(t) || isPtr(t))      => (MOVDload  ptr mem)
   260  (Load <t> ptr mem) &&  is32BitFloat(t)                 => (FMOVWload ptr mem)
   261  (Load <t> ptr mem) &&  is64BitFloat(t)                 => (FMOVDload ptr mem)
   262  
   263  // Stores
   264  (Store {t} ptr val mem) && t.Size() == 1 => (MOVBstore ptr val mem)
   265  (Store {t} ptr val mem) && t.Size() == 2 => (MOVHstore ptr val mem)
   266  (Store {t} ptr val mem) && t.Size() == 4 && !t.IsFloat() => (MOVWstore ptr val mem)
   267  (Store {t} ptr val mem) && t.Size() == 8 && !t.IsFloat() => (MOVDstore ptr val mem)
   268  (Store {t} ptr val mem) && t.Size() == 4 &&  t.IsFloat() => (FMOVWstore ptr val mem)
   269  (Store {t} ptr val mem) && t.Size() == 8 &&  t.IsFloat() => (FMOVDstore ptr val mem)
   270  
   271  // We need to fold MOVaddr into the LD/MOVDstore ops so that the live variable analysis
   272  // knows what variables are being read/written by the ops.
   273  (MOVBUload [off1] {sym1} (MOVaddr [off2] {sym2} base) mem) && is32Bit(int64(off1)+int64(off2)) && canMergeSym(sym1, sym2) =>
   274  	(MOVBUload [off1+off2] {mergeSym(sym1,sym2)} base mem)
   275  (MOVBload  [off1] {sym1} (MOVaddr [off2] {sym2} base) mem) && is32Bit(int64(off1)+int64(off2)) && canMergeSym(sym1, sym2) =>
   276  	(MOVBload  [off1+off2] {mergeSym(sym1,sym2)} base mem)
   277  (MOVHUload [off1] {sym1} (MOVaddr [off2] {sym2} base) mem) && is32Bit(int64(off1)+int64(off2)) && canMergeSym(sym1, sym2) =>
   278  	(MOVHUload [off1+off2] {mergeSym(sym1,sym2)} base mem)
   279  (MOVHload  [off1] {sym1} (MOVaddr [off2] {sym2} base) mem) && is32Bit(int64(off1)+int64(off2)) && canMergeSym(sym1, sym2) =>
   280  	(MOVHload  [off1+off2] {mergeSym(sym1,sym2)} base mem)
   281  (MOVWUload [off1] {sym1} (MOVaddr [off2] {sym2} base) mem) && is32Bit(int64(off1)+int64(off2)) && canMergeSym(sym1, sym2) =>
   282  	(MOVWUload [off1+off2] {mergeSym(sym1,sym2)} base mem)
   283  (MOVWload  [off1] {sym1} (MOVaddr [off2] {sym2} base) mem) && is32Bit(int64(off1)+int64(off2)) && canMergeSym(sym1, sym2) =>
   284  	(MOVWload  [off1+off2] {mergeSym(sym1,sym2)} base mem)
   285  (MOVDload  [off1] {sym1} (MOVaddr [off2] {sym2} base) mem) && is32Bit(int64(off1)+int64(off2)) && canMergeSym(sym1, sym2) =>
   286  	(MOVDload  [off1+off2] {mergeSym(sym1,sym2)} base mem)
   287  
   288  (MOVBstore [off1] {sym1} (MOVaddr [off2] {sym2} base) val mem) && is32Bit(int64(off1)+int64(off2)) && canMergeSym(sym1, sym2) =>
   289  	(MOVBstore [off1+off2] {mergeSym(sym1,sym2)} base val mem)
   290  (MOVHstore [off1] {sym1} (MOVaddr [off2] {sym2} base) val mem) && is32Bit(int64(off1)+int64(off2)) && canMergeSym(sym1, sym2) =>
   291  	(MOVHstore [off1+off2] {mergeSym(sym1,sym2)} base val mem)
   292  (MOVWstore [off1] {sym1} (MOVaddr [off2] {sym2} base) val mem) && is32Bit(int64(off1)+int64(off2)) && canMergeSym(sym1, sym2) =>
   293  	(MOVWstore [off1+off2] {mergeSym(sym1,sym2)} base val mem)
   294  (MOVDstore [off1] {sym1} (MOVaddr [off2] {sym2} base) val mem) && is32Bit(int64(off1)+int64(off2)) && canMergeSym(sym1, sym2) =>
   295  	(MOVDstore [off1+off2] {mergeSym(sym1,sym2)} base val mem)
   296  (MOVBstorezero [off1] {sym1} (MOVaddr [off2] {sym2} ptr) mem) && canMergeSym(sym1,sym2) && is32Bit(int64(off1)+int64(off2)) =>
   297  	(MOVBstorezero [off1+off2] {mergeSym(sym1,sym2)} ptr mem)
   298  (MOVHstorezero [off1] {sym1} (MOVaddr [off2] {sym2} ptr) mem) && canMergeSym(sym1,sym2) && is32Bit(int64(off1)+int64(off2)) =>
   299  	(MOVHstorezero [off1+off2] {mergeSym(sym1,sym2)} ptr mem)
   300  (MOVWstorezero [off1] {sym1} (MOVaddr [off2] {sym2} ptr) mem) && canMergeSym(sym1,sym2) && is32Bit(int64(off1)+int64(off2)) =>
   301  	(MOVWstorezero [off1+off2] {mergeSym(sym1,sym2)} ptr mem)
   302  (MOVDstorezero [off1] {sym1} (MOVaddr [off2] {sym2} ptr) mem) && canMergeSym(sym1,sym2) && is32Bit(int64(off1)+int64(off2)) =>
   303  	(MOVDstorezero [off1+off2] {mergeSym(sym1,sym2)} ptr mem)
   304  
   305  (MOVBUload [off1] {sym} (ADDI [off2] base) mem) && is32Bit(int64(off1)+off2) =>
   306  	(MOVBUload [off1+int32(off2)] {sym} base mem)
   307  (MOVBload  [off1] {sym} (ADDI [off2] base) mem) && is32Bit(int64(off1)+off2) =>
   308  	(MOVBload  [off1+int32(off2)] {sym} base mem)
   309  (MOVHUload [off1] {sym} (ADDI [off2] base) mem) && is32Bit(int64(off1)+off2) =>
   310  	(MOVHUload [off1+int32(off2)] {sym} base mem)
   311  (MOVHload  [off1] {sym} (ADDI [off2] base) mem) && is32Bit(int64(off1)+off2) =>
   312  	(MOVHload  [off1+int32(off2)] {sym} base mem)
   313  (MOVWUload [off1] {sym} (ADDI [off2] base) mem) && is32Bit(int64(off1)+off2) =>
   314  	(MOVWUload [off1+int32(off2)] {sym} base mem)
   315  (MOVWload  [off1] {sym} (ADDI [off2] base) mem) && is32Bit(int64(off1)+off2) =>
   316  	(MOVWload  [off1+int32(off2)] {sym} base mem)
   317  (MOVDload  [off1] {sym} (ADDI [off2] base) mem) && is32Bit(int64(off1)+off2) =>
   318  	(MOVDload  [off1+int32(off2)] {sym} base mem)
   319  
   320  (MOVBstore [off1] {sym} (ADDI [off2] base) val mem) && is32Bit(int64(off1)+off2) =>
   321  	(MOVBstore [off1+int32(off2)] {sym} base val mem)
   322  (MOVHstore [off1] {sym} (ADDI [off2] base) val mem) && is32Bit(int64(off1)+off2) =>
   323  	(MOVHstore [off1+int32(off2)] {sym} base val mem)
   324  (MOVWstore [off1] {sym} (ADDI [off2] base) val mem) && is32Bit(int64(off1)+off2) =>
   325  	(MOVWstore [off1+int32(off2)] {sym} base val mem)
   326  (MOVDstore [off1] {sym} (ADDI [off2] base) val mem) && is32Bit(int64(off1)+off2) =>
   327  	(MOVDstore [off1+int32(off2)] {sym} base val mem)
   328  (MOVBstorezero [off1] {sym} (ADDI [off2] ptr) mem) && is32Bit(int64(off1)+off2) => (MOVBstorezero [off1+int32(off2)] {sym} ptr mem)
   329  (MOVHstorezero [off1] {sym} (ADDI [off2] ptr) mem) && is32Bit(int64(off1)+off2) => (MOVHstorezero [off1+int32(off2)] {sym} ptr mem)
   330  (MOVWstorezero [off1] {sym} (ADDI [off2] ptr) mem) && is32Bit(int64(off1)+off2) => (MOVWstorezero [off1+int32(off2)] {sym} ptr mem)
   331  (MOVDstorezero [off1] {sym} (ADDI [off2] ptr) mem) && is32Bit(int64(off1)+off2) => (MOVDstorezero [off1+int32(off2)] {sym} ptr mem)
   332  
   333  // Similarly, fold ADDI into MOVaddr to avoid confusing live variable analysis
   334  // with OffPtr -> ADDI.
   335  (ADDI [c] (MOVaddr [d] {s} x)) && is32Bit(c+int64(d)) => (MOVaddr [int32(c)+d] {s} x)
   336  
   337  // Small zeroing
   338  (Zero [0] _ mem) => mem
   339  (Zero [1] ptr mem) => (MOVBstore ptr (MOVDconst [0]) mem)
   340  (Zero [2] {t} ptr mem) && t.Alignment()%2 == 0 =>
   341  	(MOVHstore ptr (MOVDconst [0]) mem)
   342  (Zero [2] ptr mem) =>
   343  	(MOVBstore [1] ptr (MOVDconst [0])
   344  		(MOVBstore ptr (MOVDconst [0]) mem))
   345  (Zero [4] {t} ptr mem) && t.Alignment()%4 == 0 =>
   346  	(MOVWstore ptr (MOVDconst [0]) mem)
   347  (Zero [4] {t} ptr mem) && t.Alignment()%2 == 0 =>
   348  	(MOVHstore [2] ptr (MOVDconst [0])
   349  		(MOVHstore ptr (MOVDconst [0]) mem))
   350  (Zero [4] ptr mem) =>
   351  	(MOVBstore [3] ptr (MOVDconst [0])
   352  		(MOVBstore [2] ptr (MOVDconst [0])
   353  			(MOVBstore [1] ptr (MOVDconst [0])
   354  				(MOVBstore ptr (MOVDconst [0]) mem))))
   355  (Zero [8] {t} ptr mem) && t.Alignment()%8 == 0 =>
   356  	(MOVDstore ptr (MOVDconst [0]) mem)
   357  (Zero [8] {t} ptr mem) && t.Alignment()%4 == 0 =>
   358  	(MOVWstore [4] ptr (MOVDconst [0])
   359  		(MOVWstore ptr (MOVDconst [0]) mem))
   360  (Zero [8] {t} ptr mem) && t.Alignment()%2 == 0 =>
   361  	(MOVHstore [6] ptr (MOVDconst [0])
   362  		(MOVHstore [4] ptr (MOVDconst [0])
   363  			(MOVHstore [2] ptr (MOVDconst [0])
   364  				(MOVHstore ptr (MOVDconst [0]) mem))))
   365  
   366  (Zero [3] ptr mem) =>
   367  	(MOVBstore [2] ptr (MOVDconst [0])
   368  		(MOVBstore [1] ptr (MOVDconst [0])
   369  			(MOVBstore ptr (MOVDconst [0]) mem)))
   370  (Zero [6] {t} ptr mem) && t.Alignment()%2 == 0 =>
   371  	(MOVHstore [4] ptr (MOVDconst [0])
   372  		(MOVHstore [2] ptr (MOVDconst [0])
   373  			(MOVHstore ptr (MOVDconst [0]) mem)))
   374  (Zero [12] {t} ptr mem) && t.Alignment()%4 == 0 =>
   375  	(MOVWstore [8] ptr (MOVDconst [0])
   376  		(MOVWstore [4] ptr (MOVDconst [0])
   377  			(MOVWstore ptr (MOVDconst [0]) mem)))
   378  (Zero [16] {t} ptr mem) && t.Alignment()%8 == 0 =>
   379  	(MOVDstore [8] ptr (MOVDconst [0])
   380  		(MOVDstore ptr (MOVDconst [0]) mem))
   381  (Zero [24] {t} ptr mem) && t.Alignment()%8 == 0 =>
   382  	(MOVDstore [16] ptr (MOVDconst [0])
   383  		(MOVDstore [8] ptr (MOVDconst [0])
   384  			(MOVDstore ptr (MOVDconst [0]) mem)))
   385  (Zero [32] {t} ptr mem) && t.Alignment()%8 == 0 =>
   386  	(MOVDstore [24] ptr (MOVDconst [0])
   387  		(MOVDstore [16] ptr (MOVDconst [0])
   388  			(MOVDstore [8] ptr (MOVDconst [0])
   389  				(MOVDstore ptr (MOVDconst [0]) mem))))
   390  
   391  // Medium 8-aligned zeroing uses a Duff's device
   392  // 8 and 128 are magic constants, see runtime/mkduff.go
   393  (Zero [s] {t} ptr mem)
   394  	&& s%8 == 0 && s <= 8*128
   395  	&& t.Alignment()%8 == 0 && !config.noDuffDevice =>
   396  	(DUFFZERO [8 * (128 - s/8)] ptr mem)
   397  
   398  // Generic zeroing uses a loop
   399  (Zero [s] {t} ptr mem) =>
   400  	(LoweredZero [t.Alignment()]
   401  		ptr
   402  		(ADD <ptr.Type> ptr (MOVDconst [s-moveSize(t.Alignment(), config)]))
   403  		mem)
   404  
   405  // Checks
   406  (IsNonNil ...) => (SNEZ ...)
   407  (IsInBounds ...) => (Less64U ...)
   408  (IsSliceInBounds ...) => (Leq64U ...)
   409  
   410  // Trivial lowering
   411  (NilCheck ...) => (LoweredNilCheck ...)
   412  (GetClosurePtr ...) => (LoweredGetClosurePtr ...)
   413  (GetCallerSP ...) => (LoweredGetCallerSP ...)
   414  (GetCallerPC ...) => (LoweredGetCallerPC ...)
   415  
   416  // Write barrier.
   417  (WB ...) => (LoweredWB ...)
   418  
   419  // Publication barrier as intrinsic
   420  (PubBarrier ...) => (LoweredPubBarrier ...)
   421  
   422  (PanicBounds [kind] x y mem) && boundsABI(kind) == 0 => (LoweredPanicBoundsA [kind] x y mem)
   423  (PanicBounds [kind] x y mem) && boundsABI(kind) == 1 => (LoweredPanicBoundsB [kind] x y mem)
   424  (PanicBounds [kind] x y mem) && boundsABI(kind) == 2 => (LoweredPanicBoundsC [kind] x y mem)
   425  
   426  // Small moves
   427  (Move [0] _ _ mem) => mem
   428  (Move [1] dst src mem) => (MOVBstore dst (MOVBload src mem) mem)
   429  (Move [2] {t} dst src mem) && t.Alignment()%2 == 0 =>
   430  	(MOVHstore dst (MOVHload src mem) mem)
   431  (Move [2] dst src mem) =>
   432  	(MOVBstore [1] dst (MOVBload [1] src mem)
   433  		(MOVBstore dst (MOVBload src mem) mem))
   434  (Move [4] {t} dst src mem) && t.Alignment()%4 == 0 =>
   435  	(MOVWstore dst (MOVWload src mem) mem)
   436  (Move [4] {t} dst src mem) && t.Alignment()%2 == 0 =>
   437  	(MOVHstore [2] dst (MOVHload [2] src mem)
   438  		(MOVHstore dst (MOVHload src mem) mem))
   439  (Move [4] dst src mem) =>
   440  	(MOVBstore [3] dst (MOVBload [3] src mem)
   441  		(MOVBstore [2] dst (MOVBload [2] src mem)
   442  			(MOVBstore [1] dst (MOVBload [1] src mem)
   443  				(MOVBstore dst (MOVBload src mem) mem))))
   444  (Move [8] {t} dst src mem) && t.Alignment()%8 == 0 =>
   445  	(MOVDstore dst (MOVDload src mem) mem)
   446  (Move [8] {t} dst src mem) && t.Alignment()%4 == 0 =>
   447  	(MOVWstore [4] dst (MOVWload [4] src mem)
   448  		(MOVWstore dst (MOVWload src mem) mem))
   449  (Move [8] {t} dst src mem) && t.Alignment()%2 == 0 =>
   450  	(MOVHstore [6] dst (MOVHload [6] src mem)
   451  		(MOVHstore [4] dst (MOVHload [4] src mem)
   452  			(MOVHstore [2] dst (MOVHload [2] src mem)
   453  				(MOVHstore dst (MOVHload src mem) mem))))
   454  
   455  (Move [3] dst src mem) =>
   456  	(MOVBstore [2] dst (MOVBload [2] src mem)
   457  		(MOVBstore [1] dst (MOVBload [1] src mem)
   458  			(MOVBstore dst (MOVBload src mem) mem)))
   459  (Move [6] {t} dst src mem) && t.Alignment()%2 == 0 =>
   460  	(MOVHstore [4] dst (MOVHload [4] src mem)
   461  		(MOVHstore [2] dst (MOVHload [2] src mem)
   462  			(MOVHstore dst (MOVHload src mem) mem)))
   463  (Move [12] {t} dst src mem) && t.Alignment()%4 == 0 =>
   464  	(MOVWstore [8] dst (MOVWload [8] src mem)
   465  		(MOVWstore [4] dst (MOVWload [4] src mem)
   466  			(MOVWstore dst (MOVWload src mem) mem)))
   467  (Move [16] {t} dst src mem) && t.Alignment()%8 == 0 =>
   468  	(MOVDstore [8] dst (MOVDload [8] src mem)
   469  		(MOVDstore dst (MOVDload src mem) mem))
   470  (Move [24] {t} dst src mem) && t.Alignment()%8 == 0 =>
   471  	(MOVDstore [16] dst (MOVDload [16] src mem)
   472  		(MOVDstore [8] dst (MOVDload [8] src mem)
   473  			(MOVDstore dst (MOVDload src mem) mem)))
   474  (Move [32] {t} dst src mem) && t.Alignment()%8 == 0 =>
   475  	(MOVDstore [24] dst (MOVDload [24] src mem)
   476  		(MOVDstore [16] dst (MOVDload [16] src mem)
   477  			(MOVDstore [8] dst (MOVDload [8] src mem)
   478  				(MOVDstore dst (MOVDload src mem) mem))))
   479  
   480  // Medium 8-aligned move uses a Duff's device
   481  // 16 and 128 are magic constants, see runtime/mkduff.go
   482  (Move [s] {t} dst src mem)
   483  	&& s%8 == 0 && s <= 8*128 && t.Alignment()%8 == 0
   484  	&& !config.noDuffDevice && logLargeCopy(v, s) =>
   485  	(DUFFCOPY [16 * (128 - s/8)] dst src mem)
   486  
   487  // Generic move uses a loop
   488  (Move [s] {t} dst src mem) && (s <= 16 || logLargeCopy(v, s)) =>
   489  	(LoweredMove [t.Alignment()]
   490  		dst
   491  		src
   492  		(ADDI <src.Type> [s-moveSize(t.Alignment(), config)] src)
   493  		mem)
   494  
   495  // Boolean ops; 0=false, 1=true
   496  (AndB ...) => (AND ...)
   497  (OrB  ...) => (OR  ...)
   498  (EqB  x y) => (SEQZ (SUB <typ.Bool> x y))
   499  (NeqB x y) => (SNEZ (SUB <typ.Bool> x y))
   500  (Not  ...) => (SEQZ ...)
   501  
   502  // Lowering pointer arithmetic
   503  // TODO: Special handling for SP offsets, like ARM
   504  (OffPtr [off] ptr:(SP)) && is32Bit(off) => (MOVaddr [int32(off)] ptr)
   505  (OffPtr [off] ptr) && is32Bit(off) => (ADDI [off] ptr)
   506  (OffPtr [off] ptr) => (ADD (MOVDconst [off]) ptr)
   507  
   508  (Const(64|32|16|8) [val]) => (MOVDconst [int64(val)])
   509  (Const32F [val]) => (FMVSX (MOVDconst [int64(math.Float32bits(val))]))
   510  (Const64F [val]) => (FMVDX (MOVDconst [int64(math.Float64bits(val))]))
   511  (ConstNil) => (MOVDconst [0])
   512  (ConstBool [val]) => (MOVDconst [int64(b2i(val))])
   513  
   514  (Addr {sym} base) => (MOVaddr {sym} [0] base)
   515  (LocalAddr <t> {sym} base mem) && t.Elem().HasPointers() => (MOVaddr {sym} (SPanchored base mem))
   516  (LocalAddr <t> {sym} base _)  && !t.Elem().HasPointers() => (MOVaddr {sym} base)
   517  
   518  // Calls
   519  (StaticCall  ...) => (CALLstatic  ...)
   520  (ClosureCall ...) => (CALLclosure ...)
   521  (InterCall   ...) => (CALLinter   ...)
   522  (TailCall ...) => (CALLtail ...)
   523  
   524  // Atomic Intrinsics
   525  (AtomicLoad(Ptr|64|32|8)  ...) => (LoweredAtomicLoad(64|64|32|8) ...)
   526  (AtomicStore(PtrNoWB|64|32|8) ...) => (LoweredAtomicStore(64|64|32|8) ...)
   527  (AtomicAdd(64|32) ...) => (LoweredAtomicAdd(64|32) ...)
   528  
   529  // AtomicAnd8(ptr,val) => LoweredAtomicAnd32(ptr&^3, ^((uint8(val) ^ 0xff) << ((ptr & 3) * 8)))
   530  (AtomicAnd8 ptr val mem) =>
   531  	(LoweredAtomicAnd32 (ANDI <typ.Uintptr> [^3] ptr)
   532  		(NOT <typ.UInt32> (SLL <typ.UInt32> (XORI <typ.UInt32> [0xff] (ZeroExt8to32 val))
   533  			(SLLI <typ.UInt64> [3] (ANDI <typ.UInt64> [3] ptr)))) mem)
   534  
   535  (AtomicAnd32 ...) => (LoweredAtomicAnd32 ...)
   536  
   537  (AtomicCompareAndSwap32 ptr old new mem) => (LoweredAtomicCas32 ptr (SignExt32to64 old) new mem)
   538  (AtomicCompareAndSwap64 ...) => (LoweredAtomicCas64 ...)
   539  
   540  (AtomicExchange(64|32) ...) => (LoweredAtomicExchange(64|32) ...)
   541  
   542  // AtomicOr8(ptr,val)  => LoweredAtomicOr32(ptr&^3, uint32(val)<<((ptr&3)*8))
   543  (AtomicOr8 ptr val mem) =>
   544  	(LoweredAtomicOr32 (ANDI <typ.Uintptr> [^3] ptr)
   545  		(SLL <typ.UInt32> (ZeroExt8to32 val)
   546  			(SLLI <typ.UInt64> [3] (ANDI <typ.UInt64> [3] ptr))) mem)
   547  
   548  (AtomicOr32  ...) => (LoweredAtomicOr32  ...)
   549  
   550  // Conditional branches
   551  (If cond yes no) => (BNEZ (MOVBUreg <typ.UInt64> cond) yes no)
   552  
   553  // Optimizations
   554  
   555  // Absorb SEQZ/SNEZ into branch.
   556  (BEQZ (SEQZ x) yes no) => (BNEZ x yes no)
   557  (BEQZ (SNEZ x) yes no) => (BEQZ x yes no)
   558  (BNEZ (SEQZ x) yes no) => (BEQZ x yes no)
   559  (BNEZ (SNEZ x) yes no) => (BNEZ x yes no)
   560  
   561  // Remove redundant NEG from BEQZ/BNEZ.
   562  (BEQZ (NEG x) yes no) => (BEQZ x yes no)
   563  (BNEZ (NEG x) yes no) => (BNEZ x yes no)
   564  
   565  // Negate comparison with FNES/FNED.
   566  (BEQZ (FNES <t> x y) yes no) => (BNEZ (FEQS <t> x y) yes no)
   567  (BNEZ (FNES <t> x y) yes no) => (BEQZ (FEQS <t> x y) yes no)
   568  (BEQZ (FNED <t> x y) yes no) => (BNEZ (FEQD <t> x y) yes no)
   569  (BNEZ (FNED <t> x y) yes no) => (BEQZ (FEQD <t> x y) yes no)
   570  
   571  // Convert BEQZ/BNEZ into more optimal branch conditions.
   572  (BEQZ (SUB x y) yes no) => (BEQ x y yes no)
   573  (BNEZ (SUB x y) yes no) => (BNE x y yes no)
   574  (BEQZ (SLT x y) yes no) => (BGE x y yes no)
   575  (BNEZ (SLT x y) yes no) => (BLT x y yes no)
   576  (BEQZ (SLTU x y) yes no) => (BGEU x y yes no)
   577  (BNEZ (SLTU x y) yes no) => (BLTU x y yes no)
   578  (BEQZ (SLTI [x] y) yes no) => (BGE y (MOVDconst [x]) yes no)
   579  (BNEZ (SLTI [x] y) yes no) => (BLT y (MOVDconst [x]) yes no)
   580  (BEQZ (SLTIU [x] y) yes no) => (BGEU y (MOVDconst [x]) yes no)
   581  (BNEZ (SLTIU [x] y) yes no) => (BLTU y (MOVDconst [x]) yes no)
   582  
   583  // Convert branch with zero to more optimal branch zero.
   584  (BEQ (MOVDconst [0]) cond yes no) => (BEQZ cond yes no)
   585  (BEQ cond (MOVDconst [0]) yes no) => (BEQZ cond yes no)
   586  (BNE (MOVDconst [0]) cond yes no) => (BNEZ cond yes no)
   587  (BNE cond (MOVDconst [0]) yes no) => (BNEZ cond yes no)
   588  (BLT (MOVDconst [0]) cond yes no) => (BGTZ cond yes no)
   589  (BLT cond (MOVDconst [0]) yes no) => (BLTZ cond yes no)
   590  (BGE (MOVDconst [0]) cond yes no) => (BLEZ cond yes no)
   591  (BGE cond (MOVDconst [0]) yes no) => (BGEZ cond yes no)
   592  
   593  // Remove redundant NEG from SEQZ/SNEZ.
   594  (SEQZ (NEG x)) => (SEQZ x)
   595  (SNEZ (NEG x)) => (SNEZ x)
   596  
   597  // Remove redundant SEQZ/SNEZ.
   598  (SEQZ (SEQZ x)) => (SNEZ x)
   599  (SEQZ (SNEZ x)) => (SEQZ x)
   600  (SNEZ (SEQZ x)) => (SEQZ x)
   601  (SNEZ (SNEZ x)) => (SNEZ x)
   602  
   603  // Store zero.
   604  (MOVBstore [off] {sym} ptr (MOVDconst [0]) mem) => (MOVBstorezero [off] {sym} ptr mem)
   605  (MOVHstore [off] {sym} ptr (MOVDconst [0]) mem) => (MOVHstorezero [off] {sym} ptr mem)
   606  (MOVWstore [off] {sym} ptr (MOVDconst [0]) mem) => (MOVWstorezero [off] {sym} ptr mem)
   607  (MOVDstore [off] {sym} ptr (MOVDconst [0]) mem) => (MOVDstorezero [off] {sym} ptr mem)
   608  
   609  // Boolean ops are already extended.
   610  (MOVBUreg x:((FLES|FLTS|FEQS|FNES) _ _)) => x
   611  (MOVBUreg x:((FLED|FLTD|FEQD|FNED) _ _)) => x
   612  (MOVBUreg x:((SEQZ|SNEZ) _)) => x
   613  (MOVBUreg x:((SLT|SLTU) _ _)) => x
   614  
   615  // Avoid extending when already sufficiently masked.
   616  (MOVBreg  x:(ANDI [c] y)) && c >= 0 && int64(int8(c)) == c => x
   617  (MOVHreg  x:(ANDI [c] y)) && c >= 0 && int64(int16(c)) == c => x
   618  (MOVWreg  x:(ANDI [c] y)) && c >= 0 && int64(int32(c)) == c => x
   619  (MOVBUreg x:(ANDI [c] y)) && c >= 0 && int64(uint8(c)) == c => x
   620  (MOVHUreg x:(ANDI [c] y)) && c >= 0 && int64(uint16(c)) == c => x
   621  (MOVWUreg x:(ANDI [c] y)) && c >= 0 && int64(uint32(c)) == c => x
   622  
   623  // Combine masking and zero extension.
   624  (MOVBUreg (ANDI [c] x)) && c < 0 => (ANDI [int64(uint8(c))] x)
   625  (MOVHUreg (ANDI [c] x)) && c < 0 => (ANDI [int64(uint16(c))] x)
   626  (MOVWUreg (ANDI [c] x)) && c < 0 => (AND (MOVDconst [int64(uint32(c))]) x)
   627  
   628  // Avoid sign/zero extension for consts.
   629  (MOVBreg  (MOVDconst [c])) => (MOVDconst [int64(int8(c))])
   630  (MOVHreg  (MOVDconst [c])) => (MOVDconst [int64(int16(c))])
   631  (MOVWreg  (MOVDconst [c])) => (MOVDconst [int64(int32(c))])
   632  (MOVBUreg (MOVDconst [c])) => (MOVDconst [int64(uint8(c))])
   633  (MOVHUreg (MOVDconst [c])) => (MOVDconst [int64(uint16(c))])
   634  (MOVWUreg (MOVDconst [c])) => (MOVDconst [int64(uint32(c))])
   635  
   636  // Avoid sign/zero extension after properly typed load.
   637  (MOVBreg  x:(MOVBload  _ _)) => (MOVDreg x)
   638  (MOVHreg  x:(MOVBload  _ _)) => (MOVDreg x)
   639  (MOVHreg  x:(MOVBUload _ _)) => (MOVDreg x)
   640  (MOVHreg  x:(MOVHload  _ _)) => (MOVDreg x)
   641  (MOVWreg  x:(MOVBload  _ _)) => (MOVDreg x)
   642  (MOVWreg  x:(MOVBUload _ _)) => (MOVDreg x)
   643  (MOVWreg  x:(MOVHload  _ _)) => (MOVDreg x)
   644  (MOVWreg  x:(MOVHUload _ _)) => (MOVDreg x)
   645  (MOVWreg  x:(MOVWload  _ _)) => (MOVDreg x)
   646  (MOVBUreg x:(MOVBUload _ _)) => (MOVDreg x)
   647  (MOVHUreg x:(MOVBUload _ _)) => (MOVDreg x)
   648  (MOVHUreg x:(MOVHUload _ _)) => (MOVDreg x)
   649  (MOVWUreg x:(MOVBUload _ _)) => (MOVDreg x)
   650  (MOVWUreg x:(MOVHUload _ _)) => (MOVDreg x)
   651  (MOVWUreg x:(MOVWUload _ _)) => (MOVDreg x)
   652  
   653  // Avoid zero extension after properly typed atomic operation.
   654  (MOVBUreg x:(Select0 (LoweredAtomicLoad8 _ _))) => (MOVDreg x)
   655  (MOVBUreg x:(Select0 (LoweredAtomicCas32 _ _ _ _))) => (MOVDreg x)
   656  (MOVBUreg x:(Select0 (LoweredAtomicCas64 _ _ _ _))) => (MOVDreg x)
   657  
   658  // Avoid sign extension after word arithmetic.
   659  (MOVWreg x:(ADDIW   _)) => (MOVDreg x)
   660  (MOVWreg x:(SUBW  _ _)) => (MOVDreg x)
   661  (MOVWreg x:(NEGW    _)) => (MOVDreg x)
   662  (MOVWreg x:(MULW  _ _)) => (MOVDreg x)
   663  (MOVWreg x:(DIVW  _ _)) => (MOVDreg x)
   664  (MOVWreg x:(DIVUW _ _)) => (MOVDreg x)
   665  (MOVWreg x:(REMW  _ _)) => (MOVDreg x)
   666  (MOVWreg x:(REMUW _ _)) => (MOVDreg x)
   667  (MOVWreg x:(ROLW  _ _)) => (MOVDreg x)
   668  (MOVWreg x:(RORW  _ _)) => (MOVDreg x)
   669  (MOVWreg x:(RORIW   _)) => (MOVDreg x)
   670  
   671  // Fold double extensions.
   672  (MOVBreg  x:(MOVBreg  _)) => (MOVDreg x)
   673  (MOVHreg  x:(MOVBreg  _)) => (MOVDreg x)
   674  (MOVHreg  x:(MOVBUreg _)) => (MOVDreg x)
   675  (MOVHreg  x:(MOVHreg  _)) => (MOVDreg x)
   676  (MOVWreg  x:(MOVBreg  _)) => (MOVDreg x)
   677  (MOVWreg  x:(MOVBUreg _)) => (MOVDreg x)
   678  (MOVWreg  x:(MOVHreg  _)) => (MOVDreg x)
   679  (MOVWreg  x:(MOVWreg  _)) => (MOVDreg x)
   680  (MOVBUreg x:(MOVBUreg _)) => (MOVDreg x)
   681  (MOVHUreg x:(MOVBUreg _)) => (MOVDreg x)
   682  (MOVHUreg x:(MOVHUreg _)) => (MOVDreg x)
   683  (MOVWUreg x:(MOVBUreg _)) => (MOVDreg x)
   684  (MOVWUreg x:(MOVHUreg _)) => (MOVDreg x)
   685  (MOVWUreg x:(MOVWUreg _)) => (MOVDreg x)
   686  
   687  // Do not extend before store.
   688  (MOVBstore [off] {sym} ptr (MOVBreg  x) mem) => (MOVBstore [off] {sym} ptr x mem)
   689  (MOVBstore [off] {sym} ptr (MOVHreg  x) mem) => (MOVBstore [off] {sym} ptr x mem)
   690  (MOVBstore [off] {sym} ptr (MOVWreg  x) mem) => (MOVBstore [off] {sym} ptr x mem)
   691  (MOVBstore [off] {sym} ptr (MOVBUreg x) mem) => (MOVBstore [off] {sym} ptr x mem)
   692  (MOVBstore [off] {sym} ptr (MOVHUreg x) mem) => (MOVBstore [off] {sym} ptr x mem)
   693  (MOVBstore [off] {sym} ptr (MOVWUreg x) mem) => (MOVBstore [off] {sym} ptr x mem)
   694  (MOVHstore [off] {sym} ptr (MOVHreg  x) mem) => (MOVHstore [off] {sym} ptr x mem)
   695  (MOVHstore [off] {sym} ptr (MOVWreg  x) mem) => (MOVHstore [off] {sym} ptr x mem)
   696  (MOVHstore [off] {sym} ptr (MOVHUreg x) mem) => (MOVHstore [off] {sym} ptr x mem)
   697  (MOVHstore [off] {sym} ptr (MOVWUreg x) mem) => (MOVHstore [off] {sym} ptr x mem)
   698  (MOVWstore [off] {sym} ptr (MOVWreg  x) mem) => (MOVWstore [off] {sym} ptr x mem)
   699  (MOVWstore [off] {sym} ptr (MOVWUreg x) mem) => (MOVWstore [off] {sym} ptr x mem)
   700  
   701  // Replace extend after load with alternate load where possible.
   702  (MOVBreg  <t> x:(MOVBUload [off] {sym} ptr mem)) && x.Uses == 1 && clobber(x) => @x.Block (MOVBload  <t> [off] {sym} ptr mem)
   703  (MOVHreg  <t> x:(MOVHUload [off] {sym} ptr mem)) && x.Uses == 1 && clobber(x) => @x.Block (MOVHload  <t> [off] {sym} ptr mem)
   704  (MOVWreg  <t> x:(MOVWUload [off] {sym} ptr mem)) && x.Uses == 1 && clobber(x) => @x.Block (MOVWload  <t> [off] {sym} ptr mem)
   705  (MOVBUreg <t> x:(MOVBload  [off] {sym} ptr mem)) && x.Uses == 1 && clobber(x) => @x.Block (MOVBUload <t> [off] {sym} ptr mem)
   706  (MOVHUreg <t> x:(MOVHload  [off] {sym} ptr mem)) && x.Uses == 1 && clobber(x) => @x.Block (MOVHUload <t> [off] {sym} ptr mem)
   707  (MOVWUreg <t> x:(MOVWload  [off] {sym} ptr mem)) && x.Uses == 1 && clobber(x) => @x.Block (MOVWUload <t> [off] {sym} ptr mem)
   708  
   709  // If a register move has only 1 use, just use the same register without emitting instruction
   710  // MOVnop does not emit an instruction, only for ensuring the type.
   711  (MOVDreg x) && x.Uses == 1 => (MOVDnop x)
   712  
   713  // TODO: we should be able to get rid of MOVDnop all together.
   714  // But for now, this is enough to get rid of lots of them.
   715  (MOVDnop (MOVDconst [c])) => (MOVDconst [c])
   716  
   717  // Avoid unnecessary zero and sign extension when right shifting.
   718  (SRAI <t> [x] (MOVWreg  y)) && x >= 0 && x <= 31 => (SRAIW <t> [int64(x)] y)
   719  (SRLI <t> [x] (MOVWUreg y)) && x >= 0 && x <= 31 => (SRLIW <t> [int64(x)] y)
   720  
   721  // Replace right shifts that exceed size of signed type.
   722  (SRAI <t> [x] (MOVBreg y)) && x >=  8 => (SRAI  [63] (SLLI <t> [56] y))
   723  (SRAI <t> [x] (MOVHreg y)) && x >= 16 => (SRAI  [63] (SLLI <t> [48] y))
   724  (SRAI <t> [x] (MOVWreg y)) && x >= 32 => (SRAIW [31] y)
   725  
   726  // Eliminate right shifts that exceed size of unsigned type.
   727  (SRLI <t> [x] (MOVBUreg y)) && x >=  8 => (MOVDconst <t> [0])
   728  (SRLI <t> [x] (MOVHUreg y)) && x >= 16 => (MOVDconst <t> [0])
   729  (SRLI <t> [x] (MOVWUreg y)) && x >= 32 => (MOVDconst <t> [0])
   730  
   731  // Fold constant into immediate instructions where possible.
   732  (ADD (MOVDconst <t> [val]) x) && is32Bit(val) && !t.IsPtr() => (ADDI [val] x)
   733  (AND (MOVDconst [val]) x) && is32Bit(val) => (ANDI [val] x)
   734  (OR  (MOVDconst [val]) x) && is32Bit(val) => (ORI  [val] x)
   735  (XOR (MOVDconst [val]) x) && is32Bit(val) => (XORI [val] x)
   736  (ROL  x (MOVDconst [val])) => (RORI  [int64(int8(-val)&63)] x)
   737  (ROLW x (MOVDconst [val])) => (RORIW [int64(int8(-val)&31)] x)
   738  (ROR  x (MOVDconst [val])) => (RORI  [int64(val&63)] x)
   739  (RORW x (MOVDconst [val])) => (RORIW [int64(val&31)] x)
   740  (SLL  x (MOVDconst [val])) => (SLLI [int64(val&63)] x)
   741  (SRL  x (MOVDconst [val])) => (SRLI [int64(val&63)] x)
   742  (SLLW x (MOVDconst [val])) => (SLLIW [int64(val&31)] x)
   743  (SRLW x (MOVDconst [val])) => (SRLIW [int64(val&31)] x)
   744  (SRA  x (MOVDconst [val])) => (SRAI [int64(val&63)] x)
   745  (SRAW x (MOVDconst [val])) => (SRAIW [int64(val&31)] x)
   746  (SLT  x (MOVDconst [val])) && val >= -2048 && val <= 2047 => (SLTI  [val] x)
   747  (SLTU x (MOVDconst [val])) && val >= -2048 && val <= 2047 => (SLTIU [val] x)
   748  
   749  // Replace negated left rotation with right rotation.
   750  (ROL  x (NEG y)) => (ROR  x y)
   751  (ROLW x (NEG y)) => (RORW x y)
   752  
   753  // Convert const subtraction into ADDI with negative immediate, where possible.
   754  (SUB x (MOVDconst [val])) && is32Bit(-val) => (ADDI [-val] x)
   755  (SUB <t> (MOVDconst [val]) y) && is32Bit(-val) => (NEG (ADDI <t> [-val] y))
   756  
   757  // Subtraction of zero.
   758  (SUB  x (MOVDconst [0])) => x
   759  (SUBW x (MOVDconst [0])) => (ADDIW [0] x)
   760  
   761  // Subtraction from zero.
   762  (SUB  (MOVDconst [0]) x) => (NEG x)
   763  (SUBW (MOVDconst [0]) x) => (NEGW x)
   764  
   765  // Fold negation into subtraction.
   766  (NEG (SUB x y)) => (SUB y x)
   767  (NEG <t> s:(ADDI [val] (SUB x y))) && s.Uses == 1 && is32Bit(-val) => (ADDI [-val] (SUB <t> y x))
   768  
   769  // Double negation.
   770  (NEG (NEG x)) => x
   771  
   772  // Addition of zero or two constants.
   773  (ADDI [0] x) => x
   774  (ADDI [x] (MOVDconst [y])) && is32Bit(x + y) => (MOVDconst [x + y])
   775  
   776  // ANDI with all zeros, all ones or two constants.
   777  (ANDI [0]  x) => (MOVDconst [0])
   778  (ANDI [-1] x) => x
   779  (ANDI [x] (MOVDconst [y])) => (MOVDconst [x & y])
   780  
   781  // ORI with all zeroes, all ones or two constants.
   782  (ORI [0]  x) => x
   783  (ORI [-1] x) => (MOVDconst [-1])
   784  (ORI [x] (MOVDconst [y])) => (MOVDconst [x | y])
   785  
   786  // Combine operations with immediate.
   787  (ADDI [x] (ADDI [y] z)) && is32Bit(x + y) => (ADDI [x + y] z)
   788  (ANDI [x] (ANDI [y] z)) => (ANDI [x & y] z)
   789  (ORI  [x] (ORI  [y] z)) => (ORI  [x | y] z)
   790  
   791  // Negation of a constant.
   792  (NEG  (MOVDconst [x])) => (MOVDconst [-x])
   793  (NEGW (MOVDconst [x])) => (MOVDconst [int64(int32(-x))])
   794  
   795  // Shift of a constant.
   796  (SLLI [x] (MOVDconst [y])) && is32Bit(y << uint32(x)) => (MOVDconst [y << uint32(x)])
   797  (SRLI [x] (MOVDconst [y])) => (MOVDconst [int64(uint64(y) >> uint32(x))])
   798  (SRAI [x] (MOVDconst [y])) => (MOVDconst [int64(y) >> uint32(x)])
   799  
   800  // SLTI/SLTIU with constants.
   801  (SLTI  [x] (MOVDconst [y])) => (MOVDconst [b2i(int64(y) < int64(x))])
   802  (SLTIU [x] (MOVDconst [y])) => (MOVDconst [b2i(uint64(y) < uint64(x))])
   803  
   804  // SLTI/SLTIU with known outcomes.
   805  (SLTI  [x] (ANDI [y] _)) && y >= 0 && int64(y) < int64(x) => (MOVDconst [1])
   806  (SLTIU [x] (ANDI [y] _)) && y >= 0 && uint64(y) < uint64(x) => (MOVDconst [1])
   807  (SLTI  [x] (ORI  [y] _)) && y >= 0 && int64(y) >= int64(x) => (MOVDconst [0])
   808  (SLTIU [x] (ORI  [y] _)) && y >= 0 && uint64(y) >= uint64(x) => (MOVDconst [0])
   809  
   810  // SLT/SLTU with known outcomes.
   811  (SLT  x x) => (MOVDconst [0])
   812  (SLTU x x) => (MOVDconst [0])
   813  
   814  // Deadcode for LoweredMuluhilo
   815  (Select0 m:(LoweredMuluhilo x y)) && m.Uses == 1 => (MULHU x y)
   816  (Select1 m:(LoweredMuluhilo x y)) && m.Uses == 1 => (MUL x y)
   817  
   818  (FADD(S|D) a (FMUL(S|D) x y)) && a.Block.Func.useFMA(v) => (FMADD(S|D) x y a)
   819  (FSUB(S|D) a (FMUL(S|D) x y)) && a.Block.Func.useFMA(v) => (FNMSUB(S|D) x y a)
   820  (FSUB(S|D) (FMUL(S|D) x y) a) && a.Block.Func.useFMA(v) => (FMSUB(S|D) x y a)
   821  
   822  // Merge negation into fused multiply-add and multiply-subtract.
   823  //
   824  // Key:
   825  //
   826  //   [+ -](x * y [+ -] z).
   827  //    _ N         A S
   828  //                D U
   829  //                D B
   830  //
   831  // Note: multiplication commutativity handled by rule generator.
   832  (F(MADD|NMADD|MSUB|NMSUB)S neg:(FNEGS x) y z) && neg.Uses == 1 => (F(NMSUB|MSUB|NMADD|MADD)S x y z)
   833  (F(MADD|NMADD|MSUB|NMSUB)S x y neg:(FNEGS z)) && neg.Uses == 1 => (F(MSUB|NMSUB|MADD|NMADD)S x y z)
   834  (F(MADD|NMADD|MSUB|NMSUB)D neg:(FNEGD x) y z) && neg.Uses == 1 => (F(NMSUB|MSUB|NMADD|MADD)D x y z)
   835  (F(MADD|NMADD|MSUB|NMSUB)D x y neg:(FNEGD z)) && neg.Uses == 1 => (F(MSUB|NMSUB|MADD|NMADD)D x y z)
   836  
   837  //
   838  // Optimisations for rva22u64 and above.
   839  //
   840  
   841  // Combine left shift and addition.
   842  (ADD (SLLI [1] x) y) && buildcfg.GORISCV64 >= 22 => (SH1ADD x y)
   843  (ADD (SLLI [2] x) y) && buildcfg.GORISCV64 >= 22 => (SH2ADD x y)
   844  (ADD (SLLI [3] x) y) && buildcfg.GORISCV64 >= 22 => (SH3ADD x y)
   845  
   846  // Integer minimum and maximum.
   847  (Min64  x y) && buildcfg.GORISCV64 >= 22 => (MIN  x y)
   848  (Max64  x y) && buildcfg.GORISCV64 >= 22 => (MAX  x y)
   849  (Min64u x y) && buildcfg.GORISCV64 >= 22 => (MINU x y)
   850  (Max64u x y) && buildcfg.GORISCV64 >= 22 => (MAXU x y)
   851  

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