LEA code size optimization pass (Part 1): Remove redundant address recalculations, by Andrey Turetsky
Add new x86 pass which replaces address calculations in load or store instructions with def register of existing LEA (must be in the same basic block), if the LEA calculates address that differs only by a displacement. Works only with -Os or -Oz.
Differential Revision: http://reviews.llvm.org/D13294
llvm-svn: 254712
diff --git a/llvm/lib/Target/X86/X86TargetMachine.cpp b/llvm/lib/Target/X86/X86TargetMachine.cpp
index 2e869eb..0e7e4c0 100644
--- a/llvm/lib/Target/X86/X86TargetMachine.cpp
+++ b/llvm/lib/Target/X86/X86TargetMachine.cpp
@@ -254,6 +254,9 @@
}
void X86PassConfig::addPreRegAlloc() {
+ if (getOptLevel() != CodeGenOpt::None)
+ addPass(createX86OptimizeLEAs());
+
addPass(createX86CallFrameOptimization());
}