X86: correct tail return address calculation

Due to the weird and wondeful usual arithmetic conversions, some
calculations involving negative values were getting performed in
uint32_t and then promoted to int64_t, which is really not a good
idea.

Patch by Katsuhiro Ueno.

llvm-svn: 187703

1 files changed, 19 insertions, 0 deletions

diff --git a/llvm/test/CodeGen/X86/tailcall-calleesave.ll b/llvm/test/CodeGen/X86/tailcall-calleesave.ll
new file mode 100644
index 00000000000..2770d0550b4
--- /dev/null
+++ b/llvm/test/CodeGen/X86/tailcall-calleesave.ll
@@ -0,0 +1,19 @@
+; RUN: llc -march=x86 -tailcallopt < %s | FileCheck %s
+
+target triple = "i686-apple-darwin"
+
+declare fastcc void @foo(i32, i32, i32, i32, i32, i32)
+declare i32* @bar(i32*)
+
+define fastcc void @hoge(i32 %b) nounwind {
+; Do not overwrite pushed callee-save registers
+; CHECK: pushl
+; CHECK: subl $[[SIZE:[0-9]+]], %esp
+; CHECK-NOT: [[SIZE]](%esp)
+  %a = alloca i32
+  store i32 0, i32* %a
+  %d = tail call i32* @bar(i32* %a) nounwind
+  store i32 %b, i32* %d
+  tail call fastcc void @foo(i32 1, i32 2, i32 3, i32 4, i32 5, i32 6) nounwind
+  ret void
+}