| ; RUN: opt < %s -instcombine -S | FileCheck %s |
| |
| ; A == B implies A >u B is false. |
| ; CHECK-LABEL: @test1 |
| ; CHECK-NOT: select |
| ; CHECK: call void @foo(i32 10) |
| define void @test1(i32 %a, i32 %b) { |
| %cmp1 = icmp eq i32 %a, %b |
| br i1 %cmp1, label %taken, label %end |
| |
| taken: |
| %cmp2 = icmp ugt i32 %a, %b |
| %c = select i1 %cmp2, i32 0, i32 10 |
| call void @foo(i32 %c) |
| br label %end |
| |
| end: |
| ret void |
| } |
| |
| ; If A == B is false then A != B is true. |
| ; CHECK-LABEL: @test2 |
| ; CHECK-NOT: select |
| ; CHECK: call void @foo(i32 20) |
| define void @test2(i32 %a, i32 %b) { |
| %cmp1 = icmp eq i32 %a, %b |
| br i1 %cmp1, label %end, label %taken |
| |
| taken: |
| %cmp2 = icmp ne i32 %a, %b |
| %c = select i1 %cmp2, i32 20, i32 0 |
| call void @foo(i32 %c) |
| br label %end |
| |
| end: |
| ret void |
| } |
| |
| ; A >u 10 implies A >u 10 is true. |
| ; CHECK-LABEL: @test3 |
| ; CHECK-NOT: select |
| ; CHECK: call void @foo(i32 30) |
| define void @test3(i32 %a) { |
| %cmp1 = icmp ugt i32 %a, 10 |
| br i1 %cmp1, label %taken, label %end |
| |
| taken: |
| %cmp2 = icmp ugt i32 %a, 10 |
| %c = select i1 %cmp2, i32 30, i32 0 |
| call void @foo(i32 %c) |
| br label %end |
| |
| end: |
| ret void |
| } |
| |
| ; CHECK-LABEL: @PR23333 |
| ; CHECK-NOT: select |
| ; CHECK: ret i8 1 |
| define i8 @PR23333(i8 addrspace(1)* %ptr) { |
| %cmp = icmp eq i8 addrspace(1)* %ptr, null |
| br i1 %cmp, label %taken, label %end |
| |
| taken: |
| %cmp2 = icmp ne i8 addrspace(1)* %ptr, null |
| %res = select i1 %cmp2, i8 2, i8 1 |
| ret i8 %res |
| |
| end: |
| ret i8 0 |
| } |
| |
| ; We know the condition of the select is true based on a dominating condition. |
| ; Therefore, we can replace %cond with %len. However, now the inner icmp is |
| ; always false and can be elided. |
| ; CHECK-LABEL: @test4 |
| ; CHECK-NOT: select |
| define void @test4(i32 %len) { |
| entry: |
| %0 = call i32 @bar(i32 %len); |
| %cmp = icmp ult i32 %len, 4 |
| br i1 %cmp, label %bb, label %b1 |
| bb: |
| %cond = select i1 %cmp, i32 %len, i32 8 |
| ; CHECK-NOT: %cmp11 = icmp eq i32 %{{.*}}, 8 |
| %cmp11 = icmp eq i32 %cond, 8 |
| ; CHECK: br i1 false, label %b0, label %b1 |
| br i1 %cmp11, label %b0, label %b1 |
| |
| b0: |
| call void @foo(i32 %len) |
| br label %b1 |
| |
| b1: |
| ; CHECK: phi i32 [ %len, %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 |
| } |
| |
| ; A >u 10 implies A >u 9 is true. |
| ; CHECK-LABEL: @test5 |
| ; CHECK-NOT: select |
| ; CHECK: call void @foo(i32 30) |
| define void @test5(i32 %a) { |
| %cmp1 = icmp ugt i32 %a, 10 |
| br i1 %cmp1, label %taken, label %end |
| |
| taken: |
| %cmp2 = icmp ugt i32 %a, 9 |
| %c = select i1 %cmp2, i32 30, i32 0 |
| call void @foo(i32 %c) |
| br label %end |
| |
| end: |
| ret void |
| } |
| |
| declare void @foo(i32) |
| declare i32 @bar(i32) |