; RUN: opt < %s -mtriple=x86_64-unknown-linux-gnu -passes=instcombine -S | FileCheck %s ; Checks that the select-icmp optimization is safe in two cases declare void @foo(i32) declare i32 @bar(i32) ; don't replace 'cond' by 'len' in the home block ('bb') that ; contains the select define void @test1(i32 %len) { entry: br label %bb bb: %cmp = icmp ult i32 %len, 8 %cond = select i1 %cmp, i32 %len, i32 8 call void @foo(i32 %cond) %cmp11 = icmp eq i32 %cond, 8 br i1 %cmp11, label %for.end, label %bb for.end: ret void ; CHECK: select ; CHECK: icmp eq i32 %cond, 8 } ; don't replace 'cond' by 'len' in a block ('b1') that dominates all uses ; of the select outside the home block ('bb'), but can be reached from the home ; block on another path ('bb -> b0 -> b1') define void @test2(i32 %len) { entry: %0 = call i32 @bar(i32 %len); %cmp = icmp ult i32 %len, 4 br i1 %cmp, label %bb, label %b1 bb: %cmp2 = icmp ult i32 %0, 2 %cond = select i1 %cmp2, i32 %len, i32 8 %cmp3 = icmp eq i32 %cond, 8 br i1 %cmp3, label %b0, label %b1 b0: call void @foo(i32 %len) br label %b1 b1: ; CHECK: phi i32 [ %cond, %bb ], [ undef, %b0 ], [ %0, %entry ] %1 = phi i32 [ %cond, %bb ], [ undef, %b0 ], [ %0, %entry ] br label %ret ret: call void @foo(i32 %1) ret void }