mirror of
https://github.com/c64scene-ar/llvm-6502.git
synced 2024-07-27 13:29:50 +00:00
2ac6e2354a
instead of hoisting them, just fold them away. This occurs in the testcase for PR8041, for example. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@112669 91177308-0d34-0410-b5e6-96231b3b80d8
67 lines
1.6 KiB
LLVM
67 lines
1.6 KiB
LLVM
; RUN: opt < %s -licm -S | FileCheck %s
|
|
|
|
@X = global i32 0 ; <i32*> [#uses=1]
|
|
|
|
declare void @foo()
|
|
|
|
; This testcase tests for a problem where LICM hoists
|
|
; potentially trapping instructions when they are not guaranteed to execute.
|
|
define i32 @test1(i1 %c) {
|
|
; CHECK: @test1
|
|
%A = load i32* @X ; <i32> [#uses=2]
|
|
br label %Loop
|
|
Loop: ; preds = %LoopTail, %0
|
|
call void @foo( )
|
|
br i1 %c, label %LoopTail, label %IfUnEqual
|
|
|
|
IfUnEqual: ; preds = %Loop
|
|
; CHECK: IfUnEqual:
|
|
; CHECK-NEXT: sdiv i32 4, %A
|
|
%B1 = sdiv i32 4, %A ; <i32> [#uses=1]
|
|
br label %LoopTail
|
|
|
|
LoopTail: ; preds = %IfUnEqual, %Loop
|
|
%B = phi i32 [ 0, %Loop ], [ %B1, %IfUnEqual ] ; <i32> [#uses=1]
|
|
br i1 %c, label %Loop, label %Out
|
|
Out: ; preds = %LoopTail
|
|
%C = sub i32 %A, %B ; <i32> [#uses=1]
|
|
ret i32 %C
|
|
}
|
|
|
|
|
|
declare void @foo2(i32)
|
|
|
|
|
|
;; It is ok and desirable to hoist this potentially trapping instruction.
|
|
define i32 @test2(i1 %c) {
|
|
; CHECK: @test2
|
|
; CHECK-NEXT: load i32* @X
|
|
; CHECK-NEXT: %B = sdiv i32 4, %A
|
|
%A = load i32* @X ; <i32> [#uses=2]
|
|
br label %Loop
|
|
Loop:
|
|
;; Should have hoisted this div!
|
|
%B = sdiv i32 4, %A ; <i32> [#uses=2]
|
|
call void @foo2( i32 %B )
|
|
br i1 %c, label %Loop, label %Out
|
|
Out: ; preds = %Loop
|
|
%C = sub i32 %A, %B ; <i32> [#uses=1]
|
|
ret i32 %C
|
|
}
|
|
|
|
|
|
; This loop invariant instruction should be constant folded, not hoisted.
|
|
define i32 @test3(i1 %c) {
|
|
; CHECK: define i32 @test3
|
|
; CHECK: call void @foo2(i32 6)
|
|
%A = load i32* @X ; <i32> [#uses=2]
|
|
br label %Loop
|
|
Loop:
|
|
%B = add i32 4, 2 ; <i32> [#uses=2]
|
|
call void @foo2( i32 %B )
|
|
br i1 %c, label %Loop, label %Out
|
|
Out: ; preds = %Loop
|
|
%C = sub i32 %A, %B ; <i32> [#uses=1]
|
|
ret i32 %C
|
|
}
|