Fix PR13991: legalizing an overflowing multiplication operation is harder than

the add/sub case since in the case of multiplication you also have to check that
the operation in the larger type did not overflow.

llvm-svn: 165017

1 files changed, 14 insertions, 0 deletions

diff --git a/llvm/test/CodeGen/X86/smul-with-overflow.ll b/llvm/test/CodeGen/X86/smul-with-overflow.ll
index 7ac3840482a..2d0b2f7aa91 100644
--- a/llvm/test/CodeGen/X86/smul-with-overflow.ll
+++ b/llvm/test/CodeGen/X86/smul-with-overflow.ll
@@ -67,3 +67,17 @@ entry:
 ; CHECK: mull
 ; CHECK-NEXT: ret
 }
+
+declare { i63, i1 } @llvm.smul.with.overflow.i63(i63, i63) nounwind readnone
+
+define i1 @test5() nounwind {
+entry:
+  %res = call { i63, i1 } @llvm.smul.with.overflow.i63(i63 4, i63 4611686018427387903)
+  %sum = extractvalue { i63, i1 } %res, 0
+  %overflow = extractvalue { i63, i1 } %res, 1
+  ret i1 %overflow
+; Was returning false, should return true (not constant folded yet though).
+; PR13991
+; CHECK: test5:
+; CHECK-NOT: xorb
+}