| ; 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 |
| } |