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1; RUN: opt < %s -mtriple=x86_64-unknown-linux-gnu -passes=instcombine -S | FileCheck %s2; Checks that the select-icmp optimization is safe in two cases3declare void @foo(i32)4declare i32 @bar(i32)5 6; don't replace 'cond' by 'len' in the home block ('bb') that7; contains the select8define void @test1(i32 %len) {9entry:10 br label %bb11 12bb:13 %cmp = icmp ult i32 %len, 814 %cond = select i1 %cmp, i32 %len, i32 815 call void @foo(i32 %cond)16 %cmp11 = icmp eq i32 %cond, 817 br i1 %cmp11, label %for.end, label %bb18 19for.end:20 ret void21; CHECK: select22; CHECK: icmp eq i32 %cond, 823}24 25; don't replace 'cond' by 'len' in a block ('b1') that dominates all uses26; of the select outside the home block ('bb'), but can be reached from the home27; block on another path ('bb -> b0 -> b1')28define void @test2(i32 %len) {29entry:30 %0 = call i32 @bar(i32 %len);31 %cmp = icmp ult i32 %len, 432 br i1 %cmp, label %bb, label %b133bb:34 %cmp2 = icmp ult i32 %0, 235 %cond = select i1 %cmp2, i32 %len, i32 836 %cmp3 = icmp eq i32 %cond, 837 br i1 %cmp3, label %b0, label %b138 39b0:40 call void @foo(i32 %len)41 br label %b142 43b1:44; CHECK: phi i32 [ %cond, %bb ], [ undef, %b0 ], [ %0, %entry ]45 %1 = phi i32 [ %cond, %bb ], [ undef, %b0 ], [ %0, %entry ]46 br label %ret47 48ret:49 call void @foo(i32 %1)50 ret void51}52