; RUN: opt < %s -S -instcombine | FileCheck %s declare i32 @llvm.ctpop.i32(i32) declare i8 @llvm.ctpop.i8(i8) declare void @llvm.assume(i1) define i1 @test1(i32 %arg) { ; CHECK: @test1 ; CHECK: ret i1 false %and = and i32 %arg, 15 %cnt = call i32 @llvm.ctpop.i32(i32 %and) %res = icmp eq i32 %cnt, 9 ret i1 %res } define i1 @test2(i32 %arg) { ; CHECK: @test2 ; CHECK: ret i1 false %and = and i32 %arg, 1 %cnt = call i32 @llvm.ctpop.i32(i32 %and) %res = icmp eq i32 %cnt, 2 ret i1 %res } define i1 @test3(i32 %arg) { ; CHECK: @test3 ; CHECK: ret i1 false ;; Use an assume to make all the bits known without triggering constant ;; folding. This is trying to hit a corner case where we have to avoid ;; taking the log of 0. %assume = icmp eq i32 %arg, 0 call void @llvm.assume(i1 %assume) %cnt = call i32 @llvm.ctpop.i32(i32 %arg) %res = icmp eq i32 %cnt, 2 ret i1 %res } ; Negative test for when we know nothing define i1 @test4(i8 %arg) { ; CHECK: @test4 ; CHECK: ret i1 %res %cnt = call i8 @llvm.ctpop.i8(i8 %arg) %res = icmp eq i8 %cnt, 2 ret i1 %res }