diff options
| -rw-r--r-- | lib/Target/X86/X86InstrInfo.td | 11 |
1 files changed, 10 insertions, 1 deletions
diff --git a/lib/Target/X86/X86InstrInfo.td b/lib/Target/X86/X86InstrInfo.td index 08c3b51887..d38840083d 100644 --- a/lib/Target/X86/X86InstrInfo.td +++ b/lib/Target/X86/X86InstrInfo.td @@ -1343,7 +1343,6 @@ let isTwoAddress = 0 in { } // Shift instructions -// FIXME: provide shorter instructions when imm8 == 1 def SHL8rCL : I<0xD2, MRM4r, (ops R8 :$dst, R8 :$src), "shl{b} {%cl, $dst|$dst, %CL}", [(set R8:$dst, (shl R8:$src, CL))]>, Imp<[CL],[]>; @@ -2756,3 +2755,13 @@ def FLDCW16m : I<0xD9, MRM5m, // X87 control world = [mem16] //===----------------------------------------------------------------------===// def RDTSC : I<0x31, RawFrm, (ops), "rdtsc", []>, TB, Imp<[],[EAX,EDX]>; + + +//===----------------------------------------------------------------------===// +// Some peepholes +//===----------------------------------------------------------------------===// + +// (shl x, 1) ==> (add x, x) +def : Pat<(shl R8 :$src1, (i8 1)), (ADD8rr R8 :$src1, R8 :$src1)>; +def : Pat<(shl R16:$src1, (i8 1)), (ADD16rr R16:$src1, R16:$src1)>; +def : Pat<(shl R32:$src1, (i8 1)), (ADD32rr R32:$src1, R32:$src1)>; |