| ; RUN: opt < %s -loop-unswitch -loop-unswitch-threshold=0 -verify-loop-info -S < %s 2>&1 | FileCheck %s |
| ; RUN: opt < %s -loop-unswitch -loop-unswitch-threshold=0 -verify-loop-info -enable-mssa-loop-dependency=true -verify-memoryssa -S < %s 2>&1 | FileCheck %s |
| |
| ; This test contains two trivial unswitch condition in one loop. |
| ; LoopUnswitch pass should be able to unswitch the second one |
| ; after unswitching the first one. |
| |
| |
| ; CHECK: br i1 %cond1, label %..split_crit_edge, label %.loop_exit.split_crit_edge |
| |
| ; CHECK: ..split_crit_edge: ; preds = %0 |
| ; CHECK: br label %.split |
| |
| ; CHECK: .split: ; preds = %..split_crit_edge |
| ; CHECK: br i1 %cond2, label %.split..split.split_crit_edge, label %.split.loop_exit.split1_crit_edge |
| |
| ; CHECK: .split..split.split_crit_edge: ; preds = %.split |
| ; CHECK: br label %.split.split |
| |
| ; CHECK: .split.split: ; preds = %.split..split.split_crit_edge |
| ; CHECK: br label %loop_begin |
| |
| ; CHECK: loop_begin: ; preds = %do_something, %.split.split |
| ; CHECK: br i1 true, label %continue, label %loop_exit |
| |
| ; CHECK: continue: ; preds = %loop_begin |
| ; CHECK: %var_val = load i32, i32* %var |
| ; CHECK: br i1 true, label %do_something, label %loop_exit |
| |
| define i32 @test(i32* %var, i1 %cond1, i1 %cond2) { |
| br label %loop_begin |
| |
| loop_begin: |
| br i1 %cond1, label %continue, label %loop_exit ; first trivial condition |
| |
| continue: |
| %var_val = load i32, i32* %var |
| br i1 %cond2, label %do_something, label %loop_exit ; second trivial condition |
| |
| do_something: |
| call void @some_func() noreturn nounwind |
| br label %loop_begin |
| |
| loop_exit: |
| ret i32 0 |
| } |
| |
| |
| ; We will not be able trivially unswitch on the SwitchInst, as its input |
| ; is a constant. However, since its a constant we should be able to figure |
| ; out that the switch can be folded into a unconditional branch to %continue. |
| ; Then we unswitch on the br inst in %continue. |
| ; |
| ; CHECK: define i32 @test2( |
| ; This is an indication that the loop has been unswitched on %cond1. |
| ; CHECK: br i1 %cond1, label %..split_crit_edge, label %.loop_exit.split_crit_edge |
| |
| ; CHECK: ..split_crit_edge: ; preds = %0 |
| ; CHECK: br label %.split |
| |
| ; CHECK: .split: ; preds = %..split_crit_edge |
| ; CHECK: br label %loop_begin |
| |
| ; CHECK: loop_begin: ; preds = %do_something, %.split |
| ; CHECK: switch i32 |
| |
| ; CHECK: continue: ; preds = %loop_begin |
| ; CHECK: %var_val = load i32, i32* %var |
| ; CHECK: br i1 true, label %do_something, label %loop_exit |
| |
| define i32 @test2(i32* %var, i1 %cond1) { |
| br label %loop_begin |
| |
| loop_begin: |
| switch i32 1, label %continue [ |
| i32 0, label %loop_exit |
| i32 1, label %continue |
| ] |
| |
| continue: |
| %var_val = load i32, i32* %var |
| br i1 %cond1, label %do_something, label %loop_exit |
| |
| do_something: |
| call void @some_func() noreturn nounwind |
| br label %loop_begin |
| |
| loop_exit: |
| ret i32 0 |
| } |
| |
| declare void @some_func() noreturn |