In some cases, due to scheduling constraints we copy the EFLAGS.

[oota-llvm.git] / test / CodeGen / X86 / clobber-fi0.ll

diff --git a/test/CodeGen/X86/clobber-fi0.ll b/test/CodeGen/X86/clobber-fi0.ll
new file mode 100644 (file)
index 0000000..38a42db
--- /dev/null
+++ b/test/CodeGen/X86/clobber-fi0.ll
@@ -0,0 +1,37 @@
+; RUN: llc < %s -mcpu=generic -mtriple=x86_64-linux | FileCheck %s
+
+target datalayout = "e-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f32:32:32-f64:64:64-v64:64:64-v128:128:128-a0:0:64-s0:64:64-f80:128:128-n8:16:32:64-S128"
+target triple = "x86_64-apple-macosx10.7.0"
+
+; In the code below we need to copy the EFLAGS because of scheduling constraints.
+; When copying the EFLAGS we need to write to the stack with push/pop. This forces
+; us to emit the prolog.
+
+; CHECK: main
+; CHECK: subq{{.*}}rsp
+; CHECK: ret
+define i32 @main(i32 %arg, i8** %arg1) nounwind {
+bb:
+  %tmp = alloca i32, align 4                      ; [#uses=3 type=i32*]
+  %tmp2 = alloca i32, align 4                     ; [#uses=3 type=i32*]
+  %tmp3 = alloca i32                              ; [#uses=1 type=i32*]
+  store i32 1, i32* %tmp, align 4
+  store i32 1, i32* %tmp2, align 4
+  br label %bb4
+
+bb4:                                              ; preds = %bb4, %bb
+  %tmp6 = load i32* %tmp2, align 4                ; [#uses=1 type=i32]
+  %tmp7 = add i32 %tmp6, -1                       ; [#uses=2 type=i32]
+  store i32 %tmp7, i32* %tmp2, align 4
+  %tmp8 = icmp eq i32 %tmp7, 0                    ; [#uses=1 type=i1]
+  %tmp9 = load i32* %tmp                          ; [#uses=1 type=i32]
+  %tmp10 = add i32 %tmp9, -1              ; [#uses=1 type=i32]
+  store i32 %tmp10, i32* %tmp3
+  br i1 %tmp8, label %bb11, label %bb4
+
+bb11:                                             ; preds = %bb4
+  %tmp12 = load i32* %tmp, align 4                ; [#uses=1 type=i32]
+  ret i32 %tmp12
+}
+
+