X86: Fix the (saddo/ssub x, 1) -> incl/decl selection to check the right operand for 1.

Found by inspection.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@127247 91177308-0d34-0410-b5e6-96231b3b80d8

3 files changed, 39 insertions, 6 deletions

diff --git a/lib/Target/X86/X86ISelLowering.cpp b/lib/Target/X86/X86ISelLowering.cpp
index 511cd31c64..2eb9841a49 100644
--- a/lib/Target/X86/X86ISelLowering.cpp
+++ b/lib/Target/X86/X86ISelLowering.cpp
@@ -8834,8 +8834,8 @@ SDValue X86TargetLowering::LowerXALUO(SDValue Op, SelectionDAG &DAG) const {
   case ISD::SADDO:
     // A subtract of one will be selected as a INC. Note that INC doesn't
     // set CF, so we can't do this for UADDO.
-    if (ConstantSDNode *C = dyn_cast<ConstantSDNode>(Op))
-      if (C->getAPIntValue() == 1) {
+    if (ConstantSDNode *C = dyn_cast<ConstantSDNode>(RHS))
+      if (C->isOne()) {
         BaseOp = X86ISD::INC;
         Cond = X86::COND_O;
         break;
@@ -8850,8 +8850,8 @@ SDValue X86TargetLowering::LowerXALUO(SDValue Op, SelectionDAG &DAG) const {
   case ISD::SSUBO:
     // A subtract of one will be selected as a DEC. Note that DEC doesn't
     // set CF, so we can't do this for USUBO.
-    if (ConstantSDNode *C = dyn_cast<ConstantSDNode>(Op))
-      if (C->getAPIntValue() == 1) {
+    if (ConstantSDNode *C = dyn_cast<ConstantSDNode>(RHS))
+      if (C->isOne()) {
         BaseOp = X86ISD::DEC;
         Cond = X86::COND_O;
         break;
diff --git a/test/CodeGen/X86/add.ll b/test/CodeGen/X86/add.ll
index 62c898025c..b95e5b53c2 100644
--- a/test/CodeGen/X86/add.ll
+++ b/test/CodeGen/X86/add.ll
@@ -133,3 +133,18 @@ define i32 @test9(i32 %x, i32 %y) nounwind readnone {
 ; X64: subl
 ; X64: ret
 }
+
+define i1 @test10(i32 %x) nounwind {
+entry:
+  %t = call {i32, i1} @llvm.sadd.with.overflow.i32(i32 %x, i32 1)
+  %obit = extractvalue {i32, i1} %t, 1
+  ret i1 %obit
+
+; X32: test10:
+; X32: incl
+; X32-NEXT: seto
+
+; X64: test10:
+; X64: incl
+; X64-NEXT: seto
+}
diff --git a/test/CodeGen/X86/sub-with-overflow.ll b/test/CodeGen/X86/sub-with-overflow.ll
index 19f4079abb..4522e917d3 100644
--- a/test/CodeGen/X86/sub-with-overflow.ll
+++ b/test/CodeGen/X86/sub-with-overflow.ll
@@ -1,5 +1,4 @@
-; RUN: llc < %s -march=x86 | grep {jo} | count 1
-; RUN: llc < %s -march=x86 | grep {jb} | count 1
+; RUN: llc < %s -march=x86 | FileCheck %s
 
 @ok = internal constant [4 x i8] c"%d\0A\00"
 @no = internal constant [4 x i8] c"no\0A\00"
@@ -18,6 +17,10 @@ normal:
 overflow:
   %t2 = tail call i32 (i8*, ...)* @printf( i8* getelementptr ([4 x i8]* @no, i32 0, i32 0) ) nounwind
   ret i1 false
+
+; CHECK: func1:
+; CHECK: subl 20(%esp)
+; CHECK-NEXT: jo
 }
 
 define i1 @func2(i32 %v1, i32 %v2) nounwind {
@@ -34,8 +37,23 @@ normal:
 carry:
   %t2 = tail call i32 (i8*, ...)* @printf( i8* getelementptr ([4 x i8]* @no, i32 0, i32 0) ) nounwind
   ret i1 false
+
+; CHECK: func2:
+; CHECK: subl 20(%esp)
+; CHECK-NEXT: jb
 }
 
 declare i32 @printf(i8*, ...) nounwind
 declare {i32, i1} @llvm.ssub.with.overflow.i32(i32, i32)
 declare {i32, i1} @llvm.usub.with.overflow.i32(i32, i32)
+
+define i1 @func3(i32 %x) nounwind {
+entry:
+  %t = call {i32, i1} @llvm.ssub.with.overflow.i32(i32 %x, i32 1)
+  %obit = extractvalue {i32, i1} %t, 1
+  ret i1 %obit
+
+; CHECK: func3:
+; CHECK: decl
+; CHECK-NEXT: seto
+}