From ffaf69b8b118808ca35ab84d477fd2e4e54cce90 Mon Sep 17 00:00:00 2001
From: Eric Christopher <echristo@apple.com>
Date: Thu, 13 Sep 2012 23:24:02 +0000
Subject: [PATCH] Fix both the test for zero and what we do if we have a zero
 for umulo legalization.

Fixes PR13839

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@163856 91177308-0d34-0410-b5e6-96231b3b80d8
---
 .../SelectionDAG/LegalizeIntegerTypes.cpp     |  5 +-
 test/CodeGen/X86/xmulo.ll                     | 50 +++++++++++++++++++
 2 files changed, 54 insertions(+), 1 deletion(-)
 create mode 100644 test/CodeGen/X86/xmulo.ll

diff --git a/lib/CodeGen/SelectionDAG/LegalizeIntegerTypes.cpp b/lib/CodeGen/SelectionDAG/LegalizeIntegerTypes.cpp
index 7d4ff3204be..1cccf1a0574 100644
--- a/lib/CodeGen/SelectionDAG/LegalizeIntegerTypes.cpp
+++ b/lib/CodeGen/SelectionDAG/LegalizeIntegerTypes.cpp
@@ -2265,12 +2265,15 @@ void DAGTypeLegalizer::ExpandIntRes_XMULO(SDNode *N,
     // A divide for UMULO will be faster than a function call. Select to
     // make sure we aren't using 0.
     SDValue isZero = DAG.getSetCC(dl, TLI.getSetCCResultType(VT),
-                                  RHS, DAG.getConstant(0, VT), ISD::SETNE);
+                                  RHS, DAG.getConstant(0, VT), ISD::SETEQ);
     SDValue NotZero = DAG.getNode(ISD::SELECT, dl, VT, isZero,
                                   DAG.getConstant(1, VT), RHS);
     SDValue DIV = DAG.getNode(ISD::UDIV, dl, VT, MUL, NotZero);
     SDValue Overflow = DAG.getSetCC(dl, N->getValueType(1), DIV, LHS,
                                     ISD::SETNE);
+    Overflow = DAG.getNode(ISD::SELECT, dl, N->getValueType(1), isZero,
+                           DAG.getConstant(0, N->getValueType(1)),
+                           Overflow);
     ReplaceValueWith(SDValue(N, 1), Overflow);
     return;
   }
diff --git a/test/CodeGen/X86/xmulo.ll b/test/CodeGen/X86/xmulo.ll
new file mode 100644
index 00000000000..486dafeb5a2
--- /dev/null
+++ b/test/CodeGen/X86/xmulo.ll
@@ -0,0 +1,50 @@
+; RUN: llc %s -o - | FileCheck %s
+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-f80:128:128-n8:16:32-S128"
+target triple = "i386-apple-macosx10.8.0"
+
+declare {i64, i1} @llvm.umul.with.overflow.i64(i64, i64) nounwind readnone
+declare i32 @printf(i8*, ...)
+
+@.str = private unnamed_addr constant [10 x i8] c"%llx, %d\0A\00", align 1
+
+define i32 @t1() nounwind {
+; CHECK: t1:
+; CHECK:  movl $0, 12(%esp)
+; CHECK:  movl $0, 8(%esp)
+; CHECK:  movl $72, 4(%esp)
+
+    %1 = call {i64, i1} @llvm.umul.with.overflow.i64(i64 9, i64 8)
+    %2 = extractvalue {i64, i1} %1, 0
+    %3 = extractvalue {i64, i1} %1, 1
+    %4 = zext i1 %3 to i32
+    %5 = call i32 (i8*, ...)* @printf(i8* getelementptr inbounds ([10 x i8]* @.str, i32 0, i32 0), i64 %2, i32 %4)
+    ret i32 0
+}
+
+define i32 @t2() nounwind {
+; CHECK: t2:
+; CHECK:  movl $0, 12(%esp)
+; CHECK:  movl $0, 8(%esp)
+; CHECK:  movl $0, 4(%esp)
+
+    %1 = call {i64, i1} @llvm.umul.with.overflow.i64(i64 9, i64 0)
+    %2 = extractvalue {i64, i1} %1, 0
+    %3 = extractvalue {i64, i1} %1, 1
+    %4 = zext i1 %3 to i32
+    %5 = call i32 (i8*, ...)* @printf(i8* getelementptr inbounds ([10 x i8]* @.str, i32 0, i32 0), i64 %2, i32 %4)
+    ret i32 0
+}
+
+define i32 @t3() nounwind {
+; CHECK: t3:
+; CHECK:  movl $1, 12(%esp)
+; CHECK:  movl $-1, 8(%esp)
+; CHECK:  movl $-9, 4(%esp)
+
+    %1 = call {i64, i1} @llvm.umul.with.overflow.i64(i64 9, i64 -1)
+    %2 = extractvalue {i64, i1} %1, 0
+    %3 = extractvalue {i64, i1} %1, 1
+    %4 = zext i1 %3 to i32
+    %5 = call i32 (i8*, ...)* @printf(i8* getelementptr inbounds ([10 x i8]* @.str, i32 0, i32 0), i64 %2, i32 %4)
+    ret i32 0
+}