Don't promote volatile loads/stores. This is needed (for example) to handle setjmp/longjmp properly.

This fixes PR1520.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@41461 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 47 insertions, 0 deletions

diff --git a/test/Transforms/Mem2Reg/2007-08-27-VolatileLoadsStores.ll b/test/Transforms/Mem2Reg/2007-08-27-VolatileLoadsStores.ll
new file mode 100644
index 0000000..579ed41
--- /dev/null
+++ b/test/Transforms/Mem2Reg/2007-08-27-VolatileLoadsStores.ll
@@ -0,0 +1,47 @@
+; RUN: llvm-as < %s | opt -std-compile-opts | llvm-dis | grep volatile | count 3
+; PR1520
+; Don't promote volatile loads/stores. This is really needed to handle setjmp/lonjmp properly.
+
+target datalayout = "e-p:32:32:32-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:32:64-f32:32:32-f64:32:64-v64:64:64-v128:128:128-a0:0:64-f80:32:32"
+target triple = "i686-pc-linux-gnu"
+	%struct.__jmp_buf_tag = type { [6 x i32], i32, %struct.__sigset_t }
+	%struct.__sigset_t = type { [32 x i32] }
+@j = external global [1 x %struct.__jmp_buf_tag]		; <[1 x %struct.__jmp_buf_tag]*> [#uses=1]
+
+define i32 @f() {
+entry:
+	%retval = alloca i32, align 4		; <i32*> [#uses=2]
+	%v = alloca i32, align 4		; <i32*> [#uses=3]
+	%tmp = alloca i32, align 4		; <i32*> [#uses=3]
+	%"alloca point" = bitcast i32 0 to i32		; <i32> [#uses=0]
+	volatile store i32 0, i32* %v, align 4
+	%tmp1 = call i32 @_setjmp( %struct.__jmp_buf_tag* getelementptr ([1 x %struct.__jmp_buf_tag]* @j, i32 0, i32 0) )		; <i32> [#uses=1]
+	%tmp2 = icmp ne i32 %tmp1, 0		; <i1> [#uses=1]
+	%tmp23 = zext i1 %tmp2 to i8		; <i8> [#uses=1]
+	%toBool = icmp ne i8 %tmp23, 0		; <i1> [#uses=1]
+	br i1 %toBool, label %bb, label %bb5
+
+bb:		; preds = %entry
+	%tmp4 = volatile load i32* %v, align 4		; <i32> [#uses=1]
+	store i32 %tmp4, i32* %tmp, align 4
+	br label %bb6
+
+bb5:		; preds = %entry
+	volatile store i32 1, i32* %v, align 4
+	call void @g( )
+	store i32 0, i32* %tmp, align 4
+	br label %bb6
+
+bb6:		; preds = %bb5, %bb
+	%tmp7 = load i32* %tmp, align 4		; <i32> [#uses=1]
+	store i32 %tmp7, i32* %retval, align 4
+	br label %return
+
+return:		; preds = %bb6
+	%retval8 = load i32* %retval		; <i32> [#uses=1]
+	ret i32 %retval8
+}
+
+declare i32 @_setjmp(%struct.__jmp_buf_tag*)
+
+declare void @g()