; RUN: opt -passes=loop-vectorize -force-vector-interleave=1 -force-vector-width=4 -S < %s | FileCheck %s --check-prefix=CHECK-VF4IC1 --check-prefix=CHECK ; RUN: opt -passes=loop-vectorize -force-vector-interleave=4 -force-vector-width=4 -S < %s | FileCheck %s --check-prefix=CHECK-VF4IC4 --check-prefix=CHECK ; RUN: opt -passes=loop-vectorize -force-vector-interleave=4 -force-vector-width=1 -S < %s | FileCheck %s --check-prefix=CHECK-VF1IC4 --check-prefix=CHECK define i32 @select_const_i32_from_icmp(ptr nocapture readonly %v, i64 %n) { ; CHECK-LABEL: @select_const_i32_from_icmp ; CHECK-VF4IC1: vector.body: ; CHECK-VF4IC1: [[VEC_PHI:%.*]] = phi <4 x i32> [ , %vector.ph ], [ [[VEC_SEL:%.*]], %vector.body ] ; CHECK-VF4IC1: [[VEC_LOAD:%.*]] = load <4 x i32> ; CHECK-VF4IC1-NEXT: [[VEC_ICMP:%.*]] = icmp eq <4 x i32> [[VEC_LOAD]], ; CHECK-VF4IC1-NEXT: [[VEC_SEL]] = select <4 x i1> [[VEC_ICMP]], <4 x i32> [[VEC_PHI]], <4 x i32> ; CHECK-VF4IC1: middle.block: ; CHECK-VF4IC1-NEXT: [[FIN_ICMP:%.*]] = icmp ne <4 x i32> [[VEC_SEL]], ; CHECK-VF4IC1-NEXT: [[OR_RDX:%.*]] = call i1 @llvm.vector.reduce.or.v4i1(<4 x i1> [[FIN_ICMP]]) ; CHECK-VF4IC1-NEXT: {{.*}} = select i1 [[OR_RDX]], i32 7, i32 3 ; CHECK-VF4IC4: vector.body: ; CHECK-VF4IC4: [[VEC_PHI1:%.*]] = phi <4 x i32> [ , %vector.ph ], [ [[VEC_SEL1:%.*]], %vector.body ] ; CHECK-VF4IC4-NEXT: [[VEC_PHI2:%.*]] = phi <4 x i32> [ , %vector.ph ], [ [[VEC_SEL2:%.*]], %vector.body ] ; CHECK-VF4IC4-NEXT: [[VEC_PHI3:%.*]] = phi <4 x i32> [ , %vector.ph ], [ [[VEC_SEL3:%.*]], %vector.body ] ; CHECK-VF4IC4-NEXT: [[VEC_PHI4:%.*]] = phi <4 x i32> [ , %vector.ph ], [ [[VEC_SEL4:%.*]], %vector.body ] ; CHECK-VF4IC4: [[VEC_ICMP1:%.*]] = icmp eq <4 x i32> {{.*}}, ; CHECK-VF4IC4-NEXT: [[VEC_ICMP2:%.*]] = icmp eq <4 x i32> {{.*}}, ; CHECK-VF4IC4-NEXT: [[VEC_ICMP3:%.*]] = icmp eq <4 x i32> {{.*}}, ; CHECK-VF4IC4-NEXT: [[VEC_ICMP4:%.*]] = icmp eq <4 x i32> {{.*}}, ; CHECK-VF4IC4-NEXT: [[VEC_SEL1:%.*]] = select <4 x i1> [[VEC_ICMP1]], <4 x i32> [[VEC_PHI1]], <4 x i32> ; CHECK-VF4IC4-NEXT: [[VEC_SEL2:%.*]] = select <4 x i1> [[VEC_ICMP2]], <4 x i32> [[VEC_PHI2]], <4 x i32> ; CHECK-VF4IC4-NEXT: [[VEC_SEL3:%.*]] = select <4 x i1> [[VEC_ICMP3]], <4 x i32> [[VEC_PHI3]], <4 x i32> ; CHECK-VF4IC4-NEXT: [[VEC_SEL4:%.*]] = select <4 x i1> [[VEC_ICMP4]], <4 x i32> [[VEC_PHI4]], <4 x i32> ; CHECK-VF4IC4: middle.block: ; CHECK-VF4IC4-NEXT: [[VEC_ICMP5:%.*]] = icmp ne <4 x i32> [[VEC_SEL1]], ; CHECK-VF4IC4-NEXT: [[VEC_SEL5:%.*]] = select <4 x i1> [[VEC_ICMP5]], <4 x i32> [[VEC_SEL1]], <4 x i32> [[VEC_SEL2]] ; CHECK-VF4IC4-NEXT: [[VEC_ICMP6:%.*]] = icmp ne <4 x i32> [[VEC_SEL5]], ; CHECK-VF4IC4-NEXT: [[VEC_SEL6:%.*]] = select <4 x i1> [[VEC_ICMP6]], <4 x i32> [[VEC_SEL5]], <4 x i32> [[VEC_SEL3]] ; CHECK-VF4IC4-NEXT: [[VEC_ICMP7:%.*]] = icmp ne <4 x i32> [[VEC_SEL6]], ; CHECK-VF4IC4-NEXT: [[VEC_SEL_FIN:%.*]] = select <4 x i1> [[VEC_ICMP7]], <4 x i32> [[VEC_SEL6]], <4 x i32> [[VEC_SEL4]] ; CHECK-VF4IC4-NEXT: [[FIN_ICMP:%.*]] = icmp ne <4 x i32> [[VEC_SEL_FIN]], ; CHECK-VF4IC4-NEXT: [[OR_RDX:%.*]] = call i1 @llvm.vector.reduce.or.v4i1(<4 x i1> [[FIN_ICMP]]) ; CHECK-VF4IC4-NEXT: {{.*}} = select i1 [[OR_RDX]], i32 7, i32 3 ; CHECK-VF1IC4: vector.body: ; CHECK-VF1IC4: [[VEC_PHI1:%.*]] = phi i32 [ 3, %vector.ph ], [ [[VEC_SEL1:%.*]], %vector.body ] ; CHECK-VF1IC4-NEXT: [[VEC_PHI2:%.*]] = phi i32 [ 3, %vector.ph ], [ [[VEC_SEL2:%.*]], %vector.body ] ; CHECK-VF1IC4-NEXT: [[VEC_PHI3:%.*]] = phi i32 [ 3, %vector.ph ], [ [[VEC_SEL3:%.*]], %vector.body ] ; CHECK-VF1IC4-NEXT: [[VEC_PHI4:%.*]] = phi i32 [ 3, %vector.ph ], [ [[VEC_SEL4:%.*]], %vector.body ] ; CHECK-VF1IC4: [[VEC_LOAD1:%.*]] = load i32 ; CHECK-VF1IC4-NEXT: [[VEC_LOAD2:%.*]] = load i32 ; CHECK-VF1IC4-NEXT: [[VEC_LOAD3:%.*]] = load i32 ; CHECK-VF1IC4-NEXT: [[VEC_LOAD4:%.*]] = load i32 ; CHECK-VF1IC4-NEXT: [[VEC_ICMP1:%.*]] = icmp eq i32 [[VEC_LOAD1]], 3 ; CHECK-VF1IC4-NEXT: [[VEC_ICMP2:%.*]] = icmp eq i32 [[VEC_LOAD2]], 3 ; CHECK-VF1IC4-NEXT: [[VEC_ICMP3:%.*]] = icmp eq i32 [[VEC_LOAD3]], 3 ; CHECK-VF1IC4-NEXT: [[VEC_ICMP4:%.*]] = icmp eq i32 [[VEC_LOAD4]], 3 ; CHECK-VF1IC4-NEXT: [[VEC_SEL1]] = select i1 [[VEC_ICMP1]], i32 [[VEC_PHI1]], i32 7 ; CHECK-VF1IC4-NEXT: [[VEC_SEL2]] = select i1 [[VEC_ICMP2]], i32 [[VEC_PHI2]], i32 7 ; CHECK-VF1IC4-NEXT: [[VEC_SEL3]] = select i1 [[VEC_ICMP3]], i32 [[VEC_PHI3]], i32 7 ; CHECK-VF1IC4-NEXT: [[VEC_SEL4]] = select i1 [[VEC_ICMP4]], i32 [[VEC_PHI4]], i32 7 ; CHECK-VF1IC4: middle.block: ; CHECK-VF1IC4-NEXT: [[VEC_ICMP4:%.*]] = icmp ne i32 [[VEC_SEL1]], 3 ; CHECK-VF1IC4-NEXT: [[VEC_SEL5:%.*]] = select i1 [[VEC_ICMP4]], i32 [[VEC_SEL1]], i32 [[VEC_SEL2]] ; CHECK-VF1IC4-NEXT: [[VEC_ICMP5:%.*]] = icmp ne i32 [[VEC_SEL5]], 3 ; CHECK-VF1IC4-NEXT: [[VEC_SEL6:%.*]] = select i1 [[VEC_ICMP5]], i32 [[VEC_SEL5]], i32 [[VEC_SEL3]] ; CHECK-VF1IC4-NEXT: [[VEC_ICMP6:%.*]] = icmp ne i32 [[VEC_SEL6]], 3 ; CHECK-VF1IC4-NEXT: {{.*}} = select i1 [[VEC_ICMP6]], i32 [[VEC_SEL6]], i32 [[VEC_SEL4]] entry: br label %for.body for.body: ; preds = %entry, %for.body %0 = phi i64 [ 0, %entry ], [ %6, %for.body ] %1 = phi i32 [ 3, %entry ], [ %5, %for.body ] %2 = getelementptr inbounds i32, ptr %v, i64 %0 %3 = load i32, ptr %2, align 4 %4 = icmp eq i32 %3, 3 %5 = select i1 %4, i32 %1, i32 7 %6 = add nuw nsw i64 %0, 1 %7 = icmp eq i64 %6, %n br i1 %7, label %exit, label %for.body exit: ; preds = %for.body ret i32 %5 } define i32 @select_const_i32_from_icmp2(ptr nocapture readonly %v, i64 %n) { ; CHECK-LABEL: @select_const_i32_from_icmp2 ; CHECK-VF4IC1: vector.body: ; CHECK-VF4IC1: [[VEC_PHI:%.*]] = phi <4 x i32> [ , %vector.ph ], [ [[VEC_SEL:%.*]], %vector.body ] ; CHECK-VF4IC1: [[VEC_LOAD:%.*]] = load <4 x i32> ; CHECK-VF4IC1-NEXT: [[VEC_ICMP:%.*]] = icmp eq <4 x i32> [[VEC_LOAD]], ; CHECK-VF4IC1-NEXT: [[VEC_SEL]] = select <4 x i1> [[VEC_ICMP]], <4 x i32> , <4 x i32> [[VEC_PHI]] ; CHECK-VF4IC1: middle.block: ; CHECK-VF4IC1-NEXT: [[FIN_ICMP:%.*]] = icmp ne <4 x i32> [[VEC_SEL]], ; CHECK-VF4IC1-NEXT: [[OR_RDX:%.*]] = call i1 @llvm.vector.reduce.or.v4i1(<4 x i1> [[FIN_ICMP]]) ; CHECK-VF4IC1-NEXT: {{.*}} = select i1 [[OR_RDX]], i32 7, i32 3 entry: br label %for.body for.body: ; preds = %entry, %for.body %0 = phi i64 [ 0, %entry ], [ %6, %for.body ] %1 = phi i32 [ 3, %entry ], [ %5, %for.body ] %2 = getelementptr inbounds i32, ptr %v, i64 %0 %3 = load i32, ptr %2, align 4 %4 = icmp eq i32 %3, 3 %5 = select i1 %4, i32 7, i32 %1 %6 = add nuw nsw i64 %0, 1 %7 = icmp eq i64 %6, %n br i1 %7, label %exit, label %for.body exit: ; preds = %for.body ret i32 %5 } define i32 @select_i32_from_icmp(ptr nocapture readonly %v, i32 %a, i32 %b, i64 %n) { ; CHECK-LABEL: @select_i32_from_icmp ; CHECK-VF4IC1: vector.ph: ; CHECK-VF4IC1: [[TMP1:%.*]] = insertelement <4 x i32> poison, i32 %a, i64 0 ; CHECK-VF4IC1-NEXT: [[SPLAT_OF_A:%.*]] = shufflevector <4 x i32> [[TMP1]], <4 x i32> poison, <4 x i32> zeroinitializer ; CHECK-VF4IC1-NEXT: [[TMP2:%.*]] = insertelement <4 x i32> poison, i32 %b, i64 0 ; CHECK-VF4IC1-NEXT: [[SPLAT_OF_B:%.*]] = shufflevector <4 x i32> [[TMP2]], <4 x i32> poison, <4 x i32> zeroinitializer ; CHECK-VF4IC1: vector.body: ; CHECK-VF4IC1: [[VEC_PHI:%.*]] = phi <4 x i32> [ [[SPLAT_OF_A]], %vector.ph ], [ [[VEC_SEL:%.*]], %vector.body ] ; CHECK-VF4IC1: [[VEC_LOAD:%.*]] = load <4 x i32> ; CHECK-VF4IC1-NEXT: [[VEC_ICMP:%.*]] = icmp eq <4 x i32> [[VEC_LOAD]], ; CHECK-VF4IC1-NEXT: [[VEC_SEL]] = select <4 x i1> [[VEC_ICMP]], <4 x i32> [[VEC_PHI]], <4 x i32> [[SPLAT_OF_B]] ; CHECK-VF4IC1: middle.block: ; CHECK-VF4IC1-NEXT: [[FIN_INS:%.*]] = insertelement <4 x i32> poison, i32 %a, i64 0 ; CHECK-VF4IC1-NEXT: [[FIN_SPLAT:%.*]] = shufflevector <4 x i32> [[FIN_INS]], <4 x i32> poison, <4 x i32> zeroinitializer ; CHECK-VF4IC1-NEXT: [[FIN_CMP:%.*]] = icmp ne <4 x i32> [[VEC_SEL]], [[FIN_SPLAT]] ; CHECK-VF4IC1-NEXT: [[OR_RDX:%.*]] = call i1 @llvm.vector.reduce.or.v4i1(<4 x i1> [[FIN_CMP]]) ; CHECK-VF4IC1-NEXT: {{.*}} = select i1 [[OR_RDX]], i32 %b, i32 %a entry: br label %for.body for.body: ; preds = %entry, %for.body %0 = phi i64 [ 0, %entry ], [ %6, %for.body ] %1 = phi i32 [ %a, %entry ], [ %5, %for.body ] %2 = getelementptr inbounds i32, ptr %v, i64 %0 %3 = load i32, ptr %2, align 4 %4 = icmp eq i32 %3, 3 %5 = select i1 %4, i32 %1, i32 %b %6 = add nuw nsw i64 %0, 1 %7 = icmp eq i64 %6, %n br i1 %7, label %exit, label %for.body exit: ; preds = %for.body ret i32 %5 } define i32 @select_const_i32_from_fcmp_fast(ptr nocapture readonly %v, i64 %n) { ; CHECK-LABEL: @select_const_i32_from_fcmp_fast ; CHECK-VF4IC1: vector.body: ; CHECK-VF4IC1: [[VEC_PHI:%.*]] = phi <4 x i32> [ , %vector.ph ], [ [[VEC_SEL:%.*]], %vector.body ] ; CHECK-VF4IC1: [[VEC_LOAD:%.*]] = load <4 x float> ; CHECK-VF4IC1-NEXT: [[VEC_FCMP:%.*]] = fcmp fast ueq <4 x float> [[VEC_LOAD]], ; CHECK-VF4IC1-NEXT: [[VEC_SEL]] = select <4 x i1> [[VEC_FCMP]], <4 x i32> [[VEC_PHI]], <4 x i32> ; CHECK-VF4IC1: middle.block: ; CHECK-VF4IC1-NEXT: [[FIN_ICMP:%.*]] = icmp ne <4 x i32> [[VEC_SEL]], ; CHECK-VF4IC1-NEXT: [[OR_RDX:%.*]] = call i1 @llvm.vector.reduce.or.v4i1(<4 x i1> [[FIN_ICMP]]) ; CHECK-VF4IC1-NEXT: {{.*}} = select i1 [[OR_RDX]], i32 1, i32 2 entry: br label %for.body for.body: ; preds = %entry, %for.body %0 = phi i64 [ 0, %entry ], [ %6, %for.body ] %1 = phi i32 [ 2, %entry ], [ %5, %for.body ] %2 = getelementptr inbounds float, ptr %v, i64 %0 %3 = load float, ptr %2, align 4 %4 = fcmp fast ueq float %3, 3.0 %5 = select i1 %4, i32 %1, i32 1 %6 = add nuw nsw i64 %0, 1 %7 = icmp eq i64 %6, %n br i1 %7, label %exit, label %for.body exit: ; preds = %for.body ret i32 %5 } define i32 @select_const_i32_from_fcmp(ptr nocapture readonly %v, i64 %n) { ; CHECK-LABEL: @select_const_i32_from_fcmp ; CHECK-VF4IC1: vector.body: ; CHECK-VF4IC1: [[VEC_PHI:%.*]] = phi <4 x i32> [ , %vector.ph ], [ [[VEC_SEL:%.*]], %vector.body ] ; CHECK-VF4IC1: [[VEC_LOAD:%.*]] = load <4 x float> ; CHECK-VF4IC1-NEXT: [[VEC_FCMP:%.*]] = fcmp ueq <4 x float> [[VEC_LOAD]], ; CHECK-VF4IC1-NEXT: [[VEC_SEL]] = select <4 x i1> [[VEC_FCMP]], <4 x i32> [[VEC_PHI]], <4 x i32> ; CHECK-VF4IC1: middle.block: ; CHECK-VF4IC1-NEXT: [[FIN_ICMP:%.*]] = icmp ne <4 x i32> [[VEC_SEL]], ; CHECK-VF4IC1-NEXT: [[OR_RDX:%.*]] = call i1 @llvm.vector.reduce.or.v4i1(<4 x i1> [[FIN_ICMP]]) ; CHECK-VF4IC1-NEXT: {{.*}} = select i1 [[OR_RDX]], i32 1, i32 2 entry: br label %for.body for.body: ; preds = %entry, %for.body %0 = phi i64 [ 0, %entry ], [ %6, %for.body ] %1 = phi i32 [ 2, %entry ], [ %5, %for.body ] %2 = getelementptr inbounds float, ptr %v, i64 %0 %3 = load float, ptr %2, align 4 %4 = fcmp ueq float %3, 3.0 %5 = select i1 %4, i32 %1, i32 1 %6 = add nuw nsw i64 %0, 1 %7 = icmp eq i64 %6, %n br i1 %7, label %exit, label %for.body exit: ; preds = %for.body ret i32 %5 } define i32 @select_i32_from_icmp_same_inputs(i32 %a, i32 %b, i64 %n) { ; CHECK-LABEL: @select_i32_from_icmp_same_inputs ; CHECK-VF4IC1: vector.ph: ; CHECK-VF4IC1: [[TMP1:%.*]] = insertelement <4 x i32> poison, i32 %a, i64 0 ; CHECK-VF4IC1-NEXT: [[SPLAT_OF_A:%.*]] = shufflevector <4 x i32> [[TMP1]], <4 x i32> poison, <4 x i32> zeroinitializer ; CHECK-VF4IC1-NEXT: [[TMP2:%.*]] = insertelement <4 x i32> poison, i32 %b, i64 0 ; CHECK-VF4IC1-NEXT: [[SPLAT_OF_B:%.*]] = shufflevector <4 x i32> [[TMP2]], <4 x i32> poison, <4 x i32> zeroinitializer ; CHECK-VF4IC1: vector.body: ; CHECK-VF4IC1: [[VEC_PHI:%.*]] = phi <4 x i32> [ [[SPLAT_OF_A]], %vector.ph ], [ [[VEC_SEL:%.*]], %vector.body ] ; CHECK-VF4IC1: [[VEC_ICMP:%.*]] = icmp eq <4 x i32> [[VEC_PHI]], ; CHECK-VF4IC1-NEXT: [[VEC_SEL]] = select <4 x i1> [[VEC_ICMP]], <4 x i32> [[VEC_PHI]], <4 x i32> [[SPLAT_OF_B]] ; CHECK-VF4IC1: middle.block: ; CHECK-VF4IC1-NEXT: [[FIN_INS:%.*]] = insertelement <4 x i32> poison, i32 %a, i64 0 ; CHECK-VF4IC1-NEXT: [[FIN_SPLAT:%.*]] = shufflevector <4 x i32> [[FIN_INS]], <4 x i32> poison, <4 x i32> zeroinitializer ; CHECK-VF4IC1-NEXT: [[FIN_CMP:%.*]] = icmp ne <4 x i32> [[VEC_SEL]], [[FIN_SPLAT]] ; CHECK-VF4IC1-NEXT: [[OR_RDX:%.*]] = call i1 @llvm.vector.reduce.or.v4i1(<4 x i1> [[FIN_CMP]]) ; CHECK-VF4IC1-NEXT: {{.*}} = select i1 [[OR_RDX]], i32 %b, i32 %a entry: br label %for.body for.body: ; preds = %entry, %for.body %0 = phi i64 [ 0, %entry ], [ %4, %for.body ] %1 = phi i32 [ %a, %entry ], [ %3, %for.body ] %2 = icmp eq i32 %1, 3 %3 = select i1 %2, i32 %1, i32 %b %4 = add nuw nsw i64 %0, 1 %5 = icmp eq i64 %4, %n br i1 %5, label %exit, label %for.body exit: ; preds = %for.body ret i32 %3 } ; Negative tests ; We don't support FP reduction variables at the moment. define float @select_const_f32_from_icmp(ptr nocapture readonly %v, i64 %n) { ; CHECK: @select_const_f32_from_icmp ; CHECK-NOT: vector.body entry: br label %for.body for.body: ; preds = %entry, %for.body %0 = phi i64 [ 0, %entry ], [ %6, %for.body ] %1 = phi fast float [ 3.0, %entry ], [ %5, %for.body ] %2 = getelementptr inbounds i32, ptr %v, i64 %0 %3 = load i32, ptr %2, align 4 %4 = icmp eq i32 %3, 3 %5 = select fast i1 %4, float %1, float 7.0 %6 = add nuw nsw i64 %0, 1 %7 = icmp eq i64 %6, %n br i1 %7, label %exit, label %for.body exit: ; preds = %for.body ret float %5 } ; We don't support select/cmp reduction patterns where there is more than one ; use of the icmp/fcmp. define i32 @select_const_i32_from_icmp_mul_use(ptr nocapture readonly %v1, ptr %v2, i64 %n) { ; CHECK-LABEL: @select_const_i32_from_icmp_mul_use ; CHECK-NOT: vector.body entry: br label %for.body for.body: ; preds = %entry, %for.body %0 = phi i64 [ 0, %entry ], [ %8, %for.body ] %1 = phi i32 [ 3, %entry ], [ %6, %for.body ] %2 = phi i32 [ 0, %entry ], [ %7, %for.body ] %3 = getelementptr inbounds i32, ptr %v1, i64 %0 %4 = load i32, ptr %3, align 4 %5 = icmp eq i32 %4, 3 %6 = select i1 %5, i32 %1, i32 7 %7 = zext i1 %5 to i32 %8 = add nuw nsw i64 %0, 1 %9 = icmp eq i64 %8, %n br i1 %9, label %exit, label %for.body exit: ; preds = %for.body store i32 %7, ptr %v2, align 4 ret i32 %6 } ; We don't support selecting loop-variant values. define i32 @select_variant_i32_from_icmp(ptr nocapture readonly %v1, ptr nocapture readonly %v2, i64 %n) { ; CHECK-LABEL: @select_variant_i32_from_icmp ; CHECK-NOT: vector.body entry: br label %for.body for.body: ; preds = %entry, %for.body %0 = phi i64 [ 0, %entry ], [ %8, %for.body ] %1 = phi i32 [ 3, %entry ], [ %7, %for.body ] %2 = getelementptr inbounds i32, ptr %v1, i64 %0 %3 = load i32, ptr %2, align 4 %4 = getelementptr inbounds i32, ptr %v2, i64 %0 %5 = load i32, ptr %4, align 4 %6 = icmp eq i32 %3, 3 %7 = select i1 %6, i32 %1, i32 %5 %8 = add nuw nsw i64 %0, 1 %9 = icmp eq i64 %8, %n br i1 %9, label %exit, label %for.body exit: ; preds = %for.body ret i32 %7 } ; We only support selects where the input comes from the same PHI as the ; reduction PHI. In the example below, the select uses the induction ; variable input and the icmp uses the reduction PHI. define i32 @select_i32_from_icmp_non_redux_phi(i32 %a, i32 %b, i32 %n) { ; CHECK-LABEL: @select_i32_from_icmp_non_redux_phi ; CHECK-NOT: vector.body entry: br label %for.body for.body: ; preds = %entry, %for.body %0 = phi i32 [ 0, %entry ], [ %4, %for.body ] %1 = phi i32 [ %a, %entry ], [ %3, %for.body ] %2 = icmp eq i32 %1, 3 %3 = select i1 %2, i32 %0, i32 %b %4 = add nuw nsw i32 %0, 1 %5 = icmp eq i32 %4, %n br i1 %5, label %exit, label %for.body exit: ; preds = %for.body ret i32 %3 }