; RUN: llc < %s -march=x86-64 -mtriple=x86_64-unknown-linux-gnu -asm-verbose=false | FileCheck %s ; These tests check for loop branching structure, and that the loop align ; directive is placed in the expected place. ; CodeGen should insert a branch into the middle of the loop in ; order to avoid a branch within the loop. ; CHECK-LABEL: simple: ; CHECK: jmp .LBB0_1 ; CHECK-NEXT: align ; CHECK-NEXT: .LBB0_2: ; CHECK-NEXT: callq loop_latch ; CHECK-NEXT: .LBB0_1: ; CHECK-NEXT: callq loop_header define void @simple() nounwind { entry: br label %loop loop: call void @loop_header() %t0 = tail call i32 @get() %t1 = icmp slt i32 %t0, 0 br i1 %t1, label %done, label %bb bb: call void @loop_latch() br label %loop done: call void @exit() ret void } ; CodeGen should move block_a to the top of the loop so that it ; falls through into the loop, avoiding a branch within the loop. ; CHECK-LABEL: slightly_more_involved: ; CHECK: jmp .LBB1_1 ; CHECK-NEXT: align ; CHECK-NEXT: .LBB1_4: ; CHECK-NEXT: callq bar99 ; CHECK-NEXT: .LBB1_1: ; CHECK-NEXT: callq body define void @slightly_more_involved() nounwind { entry: br label %loop loop: call void @body() %t0 = call i32 @get() %t1 = icmp slt i32 %t0, 2 br i1 %t1, label %block_a, label %bb bb: %t2 = call i32 @get() %t3 = icmp slt i32 %t2, 99 br i1 %t3, label %exit, label %loop block_a: call void @bar99() br label %loop exit: call void @exit() ret void } ; Same as slightly_more_involved, but block_a is now a CFG diamond with ; fallthrough edges which should be preserved. ; "callq block_a_merge_func" is tail duped. ; CHECK-LABEL: yet_more_involved: ; CHECK: jmp .LBB2_1 ; CHECK-NEXT: align ; CHECK-NEXT: .LBB2_5: ; CHECK-NEXT: callq block_a_true_func ; CHECK-NEXT: callq block_a_merge_func ; CHECK-NEXT: .LBB2_1: ; CHECK-NEXT: callq body ; ; LBB2_4 ; CHECK: callq bar99 ; CHECK-NEXT: callq get ; CHECK-NEXT: cmpl $2999, %eax ; CHECK-NEXT: jle .LBB2_5 ; CHECK-NEXT: callq block_a_false_func ; CHECK-NEXT: callq block_a_merge_func ; CHECK-NEXT: jmp .LBB2_1 define void @yet_more_involved() nounwind { entry: br label %loop loop: call void @body() %t0 = call i32 @get() %t1 = icmp slt i32 %t0, 2 br i1 %t1, label %block_a, label %bb bb: %t2 = call i32 @get() %t3 = icmp slt i32 %t2, 99 br i1 %t3, label %exit, label %loop block_a: call void @bar99() %z0 = call i32 @get() %z1 = icmp slt i32 %z0, 3000 br i1 %z1, label %block_a_true, label %block_a_false block_a_true: call void @block_a_true_func() br label %block_a_merge block_a_false: call void @block_a_false_func() br label %block_a_merge block_a_merge: call void @block_a_merge_func() br label %loop exit: call void @exit() ret void } ; CodeGen should move the CFG islands that are part of the loop but don't ; conveniently fit anywhere so that they are at least contiguous with the ; loop. ; CHECK-LABEL: cfg_islands: ; CHECK: jmp .LBB3_1 ; CHECK-NEXT: align ; CHECK-NEXT: .LBB3_7: ; CHECK-NEXT: callq bar100 ; CHECK-NEXT: .LBB3_1: ; CHECK-NEXT: callq loop_header ; CHECK: jl .LBB3_7 ; CHECK: jge .LBB3_3 ; CHECK-NEXT: callq bar101 ; CHECK-NEXT: jmp .LBB3_1 ; CHECK-NEXT: align ; CHECK-NEXT: .LBB3_3: ; CHECK: jge .LBB3_4 ; CHECK-NEXT: callq bar102 ; CHECK-NEXT: jmp .LBB3_1 ; CHECK-NEXT: .LBB3_4: ; CHECK: jl .LBB3_6 ; CHECK-NEXT: callq loop_latch ; CHECK-NEXT: jmp .LBB3_1 ; CHECK-NEXT: .LBB3_6: define void @cfg_islands() nounwind { entry: br label %loop loop: call void @loop_header() %t0 = call i32 @get() %t1 = icmp slt i32 %t0, 100 br i1 %t1, label %block100, label %bb bb: %t2 = call i32 @get() %t3 = icmp slt i32 %t2, 101 br i1 %t3, label %block101, label %bb1 bb1: %t4 = call i32 @get() %t5 = icmp slt i32 %t4, 102 br i1 %t5, label %block102, label %bb2 bb2: %t6 = call i32 @get() %t7 = icmp slt i32 %t6, 103 br i1 %t7, label %exit, label %bb3 bb3: call void @loop_latch() br label %loop exit: call void @exit() ret void block100: call void @bar100() br label %loop block101: call void @bar101() br label %loop block102: call void @bar102() br label %loop } declare void @bar99() nounwind declare void @bar100() nounwind declare void @bar101() nounwind declare void @bar102() nounwind declare void @body() nounwind declare void @exit() nounwind declare void @loop_header() nounwind declare void @loop_latch() nounwind declare i32 @get() nounwind declare void @block_a_true_func() nounwind declare void @block_a_false_func() nounwind declare void @block_a_merge_func() nounwind