Changes in directory llvm/lib/Target/X86:
X86InstrInfo.td updated: 1.189 -> 1.190
---
Log message:
Addd (shl x, 1) ==> (shl x, x) peepholes.
---
Diffs of the changes: (+10 -1)
X86InstrInfo.td | 11 ++++++++++-
1 files changed, 10 insertions(+), 1 deletion(-)
Index: llvm/lib/Target/X86/X86InstrInfo.td
diff -u llvm/lib/Target/X86/X86InstrInfo.td:1.189
llvm/lib/Target/X86/X86InstrInfo.td:1.190
--- llvm/lib/Target/X86/X86InstrInfo.td:1.189 Thu Jan 5 18:43:03 2006
+++ llvm/lib/Target/X86/X86InstrInfo.td Thu Jan 5 20:31:59 2006
@@ -1343,7 +1343,6 @@
}
// 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 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)>;
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