; RUN: opt < %s -S -instcombine | FileCheck %s @A = extern_weak global i32, align 4 @B = extern_weak global i32, align 4 define i32 @foo(i1 %which) { entry: br i1 %which, label %final, label %delay delay: br label %final ; CHECK-LABEL: @foo ; CHECK-LABEL: final: ; CHECK: phi i32 [ 1, %entry ], [ select (i1 icmp eq (i32* @A, i32* @B), i32 2, i32 1), %delay ] final: %use2 = phi i1 [ false, %entry ], [ icmp eq (i32* @A, i32* @B), %delay ] %value = select i1 %use2, i32 2, i32 1 ret i32 %value } ; test folding of select into phi for vectors. define <4 x i64> @vec1(i1 %which) { entry: br i1 %which, label %final, label %delay delay: br label %final final: ; CHECK-LABEL: @vec1 ; CHECK-LABEL: final: ; CHECK: %phinode = phi <4 x i64> [ zeroinitializer, %entry ], [ , %delay ] ; CHECK-NOT: select ; CHECK: ret <4 x i64> %phinode %phinode = phi <4 x i1> [ , %entry ], [ , %delay ] %sel = select <4 x i1> %phinode, <4 x i64> zeroinitializer, <4 x i64> ret <4 x i64> %sel } define <4 x i64> @vec2(i1 %which) { entry: br i1 %which, label %final, label %delay delay: br label %final final: ; CHECK-LABEL: @vec2 ; CHECK-LABEL: final: ; CHECK: %phinode = phi <4 x i64> [ , %entry ], [ , %delay ] ; CHECK-NOT: select ; CHECK: ret <4 x i64> %phinode %phinode = phi <4 x i1> [ , %entry ], [ , %delay ] %sel = select <4 x i1> %phinode, <4 x i64> zeroinitializer, <4 x i64> ret <4 x i64> %sel } ; Test PR33364 ; Insert the generated select into the same block as the incoming phi value. ; phi has constant vectors along with a single non-constant vector as operands. define <2 x i8> @vec3(i1 %cond1, i1 %cond2, <2 x i1> %x, <2 x i8> %y, <2 x i8> %z) { ; CHECK-LABEL: @vec3 ; CHECK: entry: ; CHECK-NEXT: [[PHITMP1:%.*]] = shufflevector <2 x i8> %y, <2 x i8> %z, <2 x i32> entry: br i1 %cond1, label %if1, label %else ; CHECK: if1: ; CHECK-NEXT: [[PHITMP2:%.*]] = shufflevector <2 x i8> %y, <2 x i8> %z, <2 x i32> if1: br i1 %cond2, label %if2, label %else ; CHECK: if2: ; CHECK-NEXT: [[PHITMP3:%.*]] = select <2 x i1> %x, <2 x i8> %y, <2 x i8> %z if2: br label %else ; CHECK: else: ; CHECK-NEXT: [[PHITMP4:%.*]] = phi <2 x i8> [ [[PHITMP3]], %if2 ], [ [[PHITMP1]], %entry ], [ [[PHITMP2]], %if1 ] ; CHECK-NEXT: ret <2 x i8> [[PHITMP4]] else: %phi = phi <2 x i1> [ %x, %if2 ], [ , %entry ], [ , %if1 ] %sel = select <2 x i1> %phi, <2 x i8> %y, <2 x i8> %z ret <2 x i8> %sel }