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authorChris Lattner <sabre@nondot.org>2009-12-23 01:30:26 +0000
committerChris Lattner <sabre@nondot.org>2009-12-23 01:30:26 +0000
commit6a3818247171ab14605fa22bc850074cb981a5be (patch)
tree4bd4de442dc51f4a239fff4008bc1ea1e6a332dc
parent0d58013c3ff43f077dc5662e6715bb4dd2cb2bc3 (diff)
stop pattern matching 16-bit zero's of a register to MOV16r0,
instead use the appropriate subreggy thing. This generates identical code on some large apps (thanks to Evan's cross class coalescing stuff he did back in july). This means that MOV16r0 can go away completely in the future soon. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@91972 91177308-0d34-0410-b5e6-96231b3b80d8
-rw-r--r--lib/Target/X86/X86InstrInfo.td14
1 files changed, 10 insertions, 4 deletions
diff --git a/lib/Target/X86/X86InstrInfo.td b/lib/Target/X86/X86InstrInfo.td
index 3f09cb0095..c25e0ebd6b 100644
--- a/lib/Target/X86/X86InstrInfo.td
+++ b/lib/Target/X86/X86InstrInfo.td
@@ -3700,15 +3700,21 @@ let Defs = [EFLAGS], isReMaterializable = 1, isAsCheapAsAMove = 1,
def MOV8r0 : I<0x30, MRMInitReg, (outs GR8 :$dst), (ins),
"xor{b}\t$dst, $dst",
[(set GR8:$dst, 0)]>;
+
+ def MOV32r0 : I<0x31, MRMInitReg, (outs GR32:$dst), (ins),
+ "xor{l}\t$dst, $dst",
+ [(set GR32:$dst, 0)]>;
+
// Use xorl instead of xorw since we don't care about the high 16 bits,
// it's smaller, and it avoids a partial-register update.
def MOV16r0 : I<0x31, MRMInitReg, (outs GR16:$dst), (ins),
- "", [(set GR16:$dst, 0)]>;
-def MOV32r0 : I<0x31, MRMInitReg, (outs GR32:$dst), (ins),
- "xor{l}\t$dst, $dst",
- [(set GR32:$dst, 0)]>;
+ "", [/*(set GR16:$dst, 0)*/]>;
}
+let AddedComplexity = 1 in
+def : Pat<(i16 0),
+ (EXTRACT_SUBREG (MOV32r0), x86_subreg_16bit)>;
+
//===----------------------------------------------------------------------===//
// Thread Local Storage Instructions
//