[ValueTracking] Improve isKnowNonZero for Ints

Improve isKnownNonZero for integers in order to improve cttz
optimizations.

Differential Revision: https://reviews.llvm.org/D60846

llvm-svn: 360222

3 files changed, 6 insertions, 12 deletions

diff --git a/llvm/test/Transforms/InstCombine/known-non-zero.ll b/llvm/test/Transforms/InstCombine/known-non-zero.ll
index 0329fbaf990..d587bfa634b 100644
--- a/llvm/test/Transforms/InstCombine/known-non-zero.ll
+++ b/llvm/test/Transforms/InstCombine/known-non-zero.ll
@@ -13,7 +13,7 @@ define i32 @test0(i64 %x) {
 ; CHECK-NEXT:    [[C:%.*]] = icmp eq i64 [[X:%.*]], 0
 ; CHECK-NEXT:    br i1 [[C]], label [[EXIT:%.*]], label [[NON_ZERO:%.*]]
 ; CHECK:       non_zero:
-; CHECK-NEXT:    [[CTZ:%.*]] = call i64 @llvm.cttz.i64(i64 [[X]], i1 false), !range !0
+; CHECK-NEXT:    [[CTZ:%.*]] = call i64 @llvm.cttz.i64(i64 [[X]], i1 true), !range !0
 ; CHECK-NEXT:    [[CTZ32:%.*]] = trunc i64 [[CTZ]] to i32
 ; CHECK-NEXT:    br label [[EXIT]]
 ; CHECK:       exit:
@@ -40,7 +40,7 @@ define i32 @test1(i64 %x) {
 ; CHECK-NEXT:    [[C:%.*]] = icmp eq i64 [[X:%.*]], 0
 ; CHECK-NEXT:    br i1 [[C]], label [[EXIT:%.*]], label [[NON_ZERO:%.*]]
 ; CHECK:       non_zero:
-; CHECK-NEXT:    [[CTZ:%.*]] = call i64 @llvm.ctlz.i64(i64 [[X]], i1 false), !range !0
+; CHECK-NEXT:    [[CTZ:%.*]] = call i64 @llvm.ctlz.i64(i64 [[X]], i1 true), !range !0
 ; CHECK-NEXT:    [[CTZ32:%.*]] = trunc i64 [[CTZ]] to i32
 ; CHECK-NEXT:    br label [[EXIT]]
 ; CHECK:       exit:
diff --git a/llvm/test/Transforms/InstSimplify/known-non-zero.ll b/llvm/test/Transforms/InstSimplify/known-non-zero.ll
index 7e819e82b90..1a985ede9a4 100644
--- a/llvm/test/Transforms/InstSimplify/known-non-zero.ll
+++ b/llvm/test/Transforms/InstSimplify/known-non-zero.ll
@@ -7,8 +7,7 @@ define i64 @test0(i64 %x) {
 ; CHECK-NEXT:    [[A:%.*]] = icmp eq i64 [[X:%.*]], 0
 ; CHECK-NEXT:    br i1 [[A]], label [[EXIT:%.*]], label [[NON_ZERO:%.*]]
 ; CHECK:       non_zero:
-; CHECK-NEXT:    [[B:%.*]] = icmp eq i64 [[X]], 0
-; CHECK-NEXT:    br i1 [[B]], label [[UNREACHABLE:%.*]], label [[EXIT]]
+; CHECK-NEXT:    br i1 false, label [[UNREACHABLE:%.*]], label [[EXIT]]
 ; CHECK:       unreachable:
 ; CHECK-NEXT:    br label [[EXIT]]
 ; CHECK:       exit:
@@ -37,8 +36,7 @@ define i64 @test1(i64 %x) {
 ; CHECK-NEXT:    [[A:%.*]] = icmp eq i64 [[X:%.*]], 0
 ; CHECK-NEXT:    br i1 [[A]], label [[EXIT:%.*]], label [[NON_ZERO:%.*]]
 ; CHECK:       non_zero:
-; CHECK-NEXT:    [[B:%.*]] = icmp ugt i64 [[X]], 0
-; CHECK-NEXT:    br i1 [[B]], label [[EXIT]], label [[UNREACHABLE:%.*]]
+; CHECK-NEXT:    br i1 true, label [[EXIT]], label [[UNREACHABLE:%.*]]
 ; CHECK:       unreachable:
 ; CHECK-NEXT:    br label [[EXIT]]
 ; CHECK:       exit:
@@ -73,11 +71,9 @@ define i1 @test2(i64 %x, i1 %y) {
 ; CHECK:       two:
 ; CHECK-NEXT:    br label [[MAINBLOCK]]
 ; CHECK:       mainblock:
-; CHECK-NEXT:    [[P:%.*]] = phi i64 [ [[X]], [[ONE]] ], [ 42, [[TWO]] ]
-; CHECK-NEXT:    [[CMP:%.*]] = icmp eq i64 [[P]], 0
 ; CHECK-NEXT:    br label [[EXIT]]
 ; CHECK:       exit:
-; CHECK-NEXT:    [[RES:%.*]] = phi i1 [ [[CMP]], [[MAINBLOCK]] ], [ true, [[START:%.*]] ]
+; CHECK-NEXT:    [[RES:%.*]] = phi i1 [ false, [[MAINBLOCK]] ], [ true, [[START:%.*]] ]
 ; CHECK-NEXT:    ret i1 [[RES]]
 ;
 start:
diff --git a/llvm/test/Transforms/LICM/hoist-mustexec.ll b/llvm/test/Transforms/LICM/hoist-mustexec.ll
index 521d3529657..59184eb542c 100644
--- a/llvm/test/Transforms/LICM/hoist-mustexec.ll
+++ b/llvm/test/Transforms/LICM/hoist-mustexec.ll
@@ -129,8 +129,6 @@ fail:
 }
 
 ; requires fact length is non-zero
-; TODO: IsKnownNonNullFromDominatingConditions is currently only be done for
-; pointers; should handle integers too
 define i32 @test4(i32* noalias nocapture readonly %a) nounwind uwtable {
 ; CHECK-LABEL: @test4(
 ; CHECK-NEXT:  entry:
@@ -138,6 +136,7 @@ define i32 @test4(i32* noalias nocapture readonly %a) nounwind uwtable {
 ; CHECK-NEXT:    [[IS_ZERO:%.*]] = icmp eq i32 [[LEN]], 0
 ; CHECK-NEXT:    br i1 [[IS_ZERO]], label [[FAIL:%.*]], label [[PREHEADER:%.*]]
 ; CHECK:       preheader:
+; CHECK-NEXT:    [[I1:%.*]] = load i32, i32* [[A]], align 4
 ; CHECK-NEXT:    br label [[FOR_BODY:%.*]]
 ; CHECK:       for.body:
 ; CHECK-NEXT:    [[IV:%.*]] = phi i32 [ 0, [[PREHEADER]] ], [ [[INC:%.*]], [[CONTINUE:%.*]] ]
@@ -145,7 +144,6 @@ define i32 @test4(i32* noalias nocapture readonly %a) nounwind uwtable {
 ; CHECK-NEXT:    [[R_CHK:%.*]] = icmp ult i32 [[IV]], [[LEN]]
 ; CHECK-NEXT:    br i1 [[R_CHK]], label [[CONTINUE]], label [[FAIL_LOOPEXIT:%.*]]
 ; CHECK:       continue:
-; CHECK-NEXT:    [[I1:%.*]] = load i32, i32* [[A]], align 4
 ; CHECK-NEXT:    [[ADD]] = add nsw i32 [[I1]], [[ACC]]
 ; CHECK-NEXT:    [[INC]] = add nuw nsw i32 [[IV]], 1
 ; CHECK-NEXT:    [[EXITCOND:%.*]] = icmp eq i32 [[INC]], 1000