llvm-6502/test/CodeGen/X86/loop-blocks.ll
Dan Gohman 07adb85cb7 Re-apply r84295, with fixes to how the loop "top" and "bottom" blocks are
tracked. Instead of trying to manually keep track of these locations
while doing complex modifications, just recompute them when they're needed.
This fixes a bug in which the TopMBB and BotMBB were not correctly updated,
leading to invalid transformations.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@84598 91177308-0d34-0410-b5e6-96231b3b80d8
2009-10-20 04:50:37 +00:00

208 lines
4.4 KiB
LLVM

; 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: simple:
; CHECK: jmp .LBB1_1
; CHECK-NEXT: align
; CHECK-NEXT: .LBB1_2:
; CHECK-NEXT: call loop_latch
; CHECK-NEXT: .LBB1_1:
; CHECK-NEXT: call 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: slightly_more_involved:
; CHECK: jmp .LBB2_1
; CHECK-NEXT: align
; CHECK-NEXT: .LBB2_4:
; CHECK-NEXT: call bar99
; CHECK-NEXT: .LBB2_1:
; CHECK-NEXT: call 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.
; CHECK: yet_more_involved:
; CHECK: jmp .LBB3_1
; CHECK-NEXT: align
; CHECK-NEXT: .LBB3_7:
; CHECK-NEXT: call block_a_true_func
; CHECK-NEXT: jmp .LBB3_4
; CHECK-NEXT: .LBB3_2:
; CHECK-NEXT: call bar99
; CHECK-NEXT: call get
; CHECK-NEXT: cmpl $2999, %eax
; CHECK-NEXT: jle .LBB3_7
; CHECK-NEXT: call block_a_false_func
; CHECK-NEXT: .LBB3_4:
; CHECK-NEXT: call block_a_merge_func
; CHECK-NEXT: .LBB3_1:
; CHECK-NEXT: call body
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: cfg_islands:
; CHECK: jmp .LBB4_1
; CHECK-NEXT: align
; CHECK-NEXT: .LBB4_7:
; CHECK-NEXT: call bar100
; CHECK-NEXT: jmp .LBB4_1
; CHECK-NEXT: .LBB4_8:
; CHECK-NEXT: call bar101
; CHECK-NEXT: jmp .LBB4_1
; CHECK-NEXT: .LBB4_9:
; CHECK-NEXT: call bar102
; CHECK-NEXT: jmp .LBB4_1
; CHECK-NEXT: .LBB4_5:
; CHECK-NEXT: call loop_latch
; CHECK-NEXT: .LBB4_1:
; CHECK-NEXT: call loop_header
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