| ; RUN: llc < %s -asm-verbose=false -verify-machineinstrs | FileCheck %s |
| |
| ;; Test that a small but nontrivial switch in a loop (like in a |
| ;; bytecode interpreter) lowers reasonably without any irreducible |
| ;; control flow being introduced. |
| |
| target triple = "wasm32" |
| |
| declare void @a(i32*) |
| declare void @b(i32*) |
| |
| ; CHECK-LABEL: switch_in_loop: |
| ; CHECK-NEXT: .functype switch_in_loop (i32, i32) -> (i32) |
| ; CHECK: global.get __stack_pointer |
| ; CHECK: global.set __stack_pointer |
| ; CHECK: block |
| ; CHECK: br_if 0 |
| ; CHECK: .LBB0_2: |
| ; CHECK: loop |
| ; CHECK: block |
| ; CHECK: block |
| ; CHECK: block |
| ; CHECK: br_table {0, 1, 2} |
| ; CHECK: .LBB0_3: |
| ; CHECK: end_block |
| ; CHECK: call a |
| ; CHECK: br 1 |
| ; CHECK: .LBB0_4: |
| ; CHECK: end_block |
| ; CHECK: call b |
| ; CHECK: .LBB0_5: |
| ; CHECK: end_block |
| ; CHECK: br_if 0 |
| ; CHECK: end_loop |
| ; CHECK: .LBB0_7: |
| ; CHECK: end_block |
| ; CHECK: global.set __stack_pointer |
| ; CHECK: end_function |
| define i32 @switch_in_loop(i32* %ops, i32 %len) { |
| entry: |
| %res = alloca i32 |
| %0 = bitcast i32* %res to i8* |
| store i32 0, i32* %res |
| %cmp6 = icmp sgt i32 %len, 0 |
| br i1 %cmp6, label %for.body, label %for.cond.cleanup |
| |
| for.cond.cleanup.loopexit: ; preds = %sw.epilog |
| %.pre = load i32, i32* %res |
| br label %for.cond.cleanup |
| |
| for.cond.cleanup: ; preds = %for.cond.cleanup.loopexit, %entry |
| %1 = phi i32 [ %.pre, %for.cond.cleanup.loopexit ], [ 0, %entry ] |
| ret i32 %1 |
| |
| for.body: ; preds = %entry, %sw.epilog |
| %i.07 = phi i32 [ %inc, %sw.epilog ], [ 0, %entry ] |
| %arrayidx = getelementptr inbounds i32, i32* %ops, i32 %i.07 |
| %2 = load i32, i32* %arrayidx |
| switch i32 %2, label %sw.epilog [ |
| i32 0, label %sw.bb |
| i32 1, label %sw.bb1 |
| ] |
| |
| sw.bb: ; preds = %for.body |
| call void @a(i32* nonnull %res) |
| br label %sw.epilog |
| |
| sw.bb1: ; preds = %for.body |
| call void @b(i32* nonnull %res) |
| br label %sw.epilog |
| |
| sw.epilog: ; preds = %for.body, %sw.bb1, %sw.bb |
| %inc = add nuw nsw i32 %i.07, 1 |
| %exitcond = icmp eq i32 %inc, %len |
| br i1 %exitcond, label %for.cond.cleanup.loopexit, label %for.body |
| } |