Don't fold and's into test instructions if they have multiple uses.

This compiles test-nofold.ll into:

_test:
	movl	$15, %ecx
	andl	4(%esp), %ecx
	testl	%ecx, %ecx
	movl	$42, %eax
	cmove	%ecx, %eax
	ret

instead of:
_test:
	movl	4(%esp), %eax
	movl	%eax, %ecx
	andl	$15, %ecx
	testl	$15, %eax
	movl	$42, %eax
	cmove	%ecx, %eax
	ret



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@47330 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 29 insertions, 0 deletions

diff --git a/test/CodeGen/X86/test-nofold.ll b/test/CodeGen/X86/test-nofold.ll
new file mode 100644
index 0000000..a24a9a0
--- /dev/null
+++ b/test/CodeGen/X86/test-nofold.ll
@@ -0,0 +1,29 @@
+; RUN: llvm-as < %s | llc -march=x86 -mcpu=yonah | grep {testl.*%e.x.*%e.x}
+; rdar://5752025
+
+; We don't want to fold the and into the test, because the and clobbers its
+; input forcing a copy.  We want:
+;	movl	$15, %ecx
+;	andl	4(%esp), %ecx
+;	testl	%ecx, %ecx
+;	movl	$42, %eax
+;	cmove	%ecx, %eax
+;	ret
+;
+; Not:
+;	movl	4(%esp), %eax
+;	movl	%eax, %ecx
+;	andl	$15, %ecx
+;	testl	$15, %eax
+;	movl	$42, %eax
+;	cmove	%ecx, %eax
+;	ret
+
+define i32 @t1(i32 %X) nounwind  {
+entry:
+	%tmp2 = and i32 %X, 15		; <i32> [#uses=2]
+	%tmp4 = icmp eq i32 %tmp2, 0		; <i1> [#uses=1]
+	%retval = select i1 %tmp4, i32 %tmp2, i32 42		; <i32> [#uses=1]
+	ret i32 %retval
+}
+