; NOTE: Assertions have been autogenerated by utils/update_test_checks.py ; RUN: opt < %s -instcombine -S | FileCheck %s declare i64 @llvm.cttz.i64(i64, i1) declare i64 @llvm.ctlz.i64(i64, i1) declare <8 x i64> @llvm.cttz.v8i64(<8 x i64>, i1) define i32 @test0(i64 %x) { ; CHECK-LABEL: @test0( ; CHECK-NEXT: start: ; 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: [[CTZ32:%.*]] = trunc i64 [[CTZ]] to i32 ; CHECK-NEXT: br label [[EXIT]] ; CHECK: exit: ; CHECK-NEXT: [[RES:%.*]] = phi i32 [ [[CTZ32]], [[NON_ZERO]] ], [ 0, [[START:%.*]] ] ; CHECK-NEXT: ret i32 [[RES]] ; start: %c = icmp eq i64 %x, 0 br i1 %c, label %exit, label %non_zero non_zero: %ctz = call i64 @llvm.cttz.i64(i64 %x, i1 false) %ctz32 = trunc i64 %ctz to i32 br label %exit exit: %res = phi i32 [ %ctz32, %non_zero ], [ 0, %start ] ret i32 %res } define i32 @test1(i64 %x) { ; CHECK-LABEL: @test1( ; CHECK-NEXT: start: ; 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: [[CTZ32:%.*]] = trunc i64 [[CTZ]] to i32 ; CHECK-NEXT: br label [[EXIT]] ; CHECK: exit: ; CHECK-NEXT: [[RES:%.*]] = phi i32 [ [[CTZ32]], [[NON_ZERO]] ], [ 0, [[START:%.*]] ] ; CHECK-NEXT: ret i32 [[RES]] ; start: %c = icmp eq i64 %x, 0 br i1 %c, label %exit, label %non_zero non_zero: %ctz = call i64 @llvm.ctlz.i64(i64 %x, i1 false) %ctz32 = trunc i64 %ctz to i32 br label %exit exit: %res = phi i32 [ %ctz32, %non_zero ], [ 0, %start ] ret i32 %res } define <8 x i64> @test2(<8 x i64> %x) { ; CHECK-LABEL: @test2( ; CHECK-NEXT: start: ; CHECK-NEXT: [[A:%.*]] = icmp eq <8 x i64> [[X:%.*]], zeroinitializer ; CHECK-NEXT: [[B:%.*]] = bitcast <8 x i1> [[A]] to i8 ; CHECK-NEXT: [[C:%.*]] = icmp eq i8 [[B]], 0 ; CHECK-NEXT: br i1 [[C]], label [[EXIT:%.*]], label [[NON_ZERO:%.*]] ; CHECK: non_zero: ; CHECK-NEXT: [[CTZ:%.*]] = call <8 x i64> @llvm.cttz.v8i64(<8 x i64> [[X]], i1 false) ; CHECK-NEXT: br label [[EXIT]] ; CHECK: exit: ; CHECK-NEXT: [[RES:%.*]] = phi <8 x i64> [ [[CTZ]], [[NON_ZERO]] ], [ zeroinitializer, [[START:%.*]] ] ; CHECK-NEXT: ret <8 x i64> [[RES]] ; start: %a = icmp eq <8 x i64> %x, zeroinitializer %b = bitcast <8 x i1> %a to i8 %c = icmp eq i8 %b, 0 br i1 %c, label %exit, label %non_zero non_zero: ; NB: We cannot determine that vectors are known to be zero based ; on the dominating condition %ctz = call <8 x i64> @llvm.cttz.v8i64(<8 x i64> %x, i1 false) br label %exit exit: %res = phi <8 x i64> [ %ctz, %non_zero ], [ zeroinitializer, %start ] ret <8 x i64> %res }