[X86] Convert esp-relative movs of function arguments to pushes, step 2
This moves the transformation introduced in r223757 into a separate MI pass.
This allows it to cover many more cases (not only cases where there must be a
reserved call frame), and perform rudimentary call folding. It still doesn't
have a heuristic, so it is enabled only for optsize/minsize, with stack
alignment <= 8, where it ought to be a fairly clear win.
Differential Revision: http://reviews.llvm.org/D6789
llvm-svn: 227728
diff --git a/llvm/lib/Target/X86/X86TargetMachine.cpp b/llvm/lib/Target/X86/X86TargetMachine.cpp
index ea37b29..2376123 100644
--- a/llvm/lib/Target/X86/X86TargetMachine.cpp
+++ b/llvm/lib/Target/X86/X86TargetMachine.cpp
@@ -192,6 +192,7 @@
void addIRPasses() override;
bool addInstSelector() override;
bool addILPOpts() override;
+ void addPreRegAlloc() override;
void addPostRegAlloc() override;
void addPreEmitPass() override;
};
@@ -225,6 +226,10 @@
return true;
}
+void X86PassConfig::addPreRegAlloc() {
+ addPass(createX86CallFrameOptimization());
+}
+
void X86PassConfig::addPostRegAlloc() {
addPass(createX86FloatingPointStackifierPass());
}