Revert "Reuse %rax after calling __chkstk on win64"
This reverts commit 01f8d579f7672872324208ac5bc4ac311e81b22e.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@185781 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Target/X86/X86ISelLowering.cpp b/lib/Target/X86/X86ISelLowering.cpp
index aaeaa5d..a6e894b 100644
--- a/lib/Target/X86/X86ISelLowering.cpp
+++ b/lib/Target/X86/X86ISelLowering.cpp
@@ -14434,11 +14434,12 @@
} else {
// __chkstk(MSVCRT): does not update stack pointer.
// Clobbers R10, R11 and EFLAGS.
+ // FIXME: RAX(allocated size) might be reused and not killed.
BuildMI(*BB, MI, DL, TII->get(X86::W64ALLOCA))
.addExternalSymbol("__chkstk")
.addReg(X86::RAX, RegState::Implicit)
.addReg(X86::EFLAGS, RegState::Define | RegState::Implicit);
- // RAX has the offset to be subtracted from RSP.
+ // RAX has the offset to subtracted from RSP.
BuildMI(*BB, MI, DL, TII->get(X86::SUB64rr), X86::RSP)
.addReg(X86::RSP)
.addReg(X86::RAX);