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llvm-project/llvm/test/CodeGen/ARM/ifcvt-iter-indbr.ll

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[CodeGen][IfCvt] Don't re-ifcvt blocks with unanalyzable terminators. If we couldn't analyze its terminator (i.e., it's an indirectbr, or some other weirdness), we can't safely re-if-convert a predicated block, because we can't tell whether the predicated terminator can fallthrough (it does). Currently, we would completely ignore the fallthrough successor. In the added testcase, this means we used to generate: ... @ %entry: cmp r5, #21 ittt ne @ %cc1f: cmpne r7, #42 @ %cc2t: strne.w r5, [r8] movne pc, r10 @ %cc1t: ... Whereas the successor of %cc1f was originally %bb1. With the fix, we get the correct: ... @ %entry: cmp r5, #21 itt eq @ %cc1t: streq.w r5, [r11] moveq pc, r0 @ %cc1f: cmp r7, #42 itt ne @ %cc2t: strne.w r5, [r8] movne pc, r10 @ %bb1: ... rdar://20192768 Differential Revision: http://reviews.llvm.org/D8509 llvm-svn: 232872
2015-03-21 09:23:15 +08:00
; RUN: llc < %s -mtriple thumbv7s-apple-darwin -asm-verbose=false | FileCheck %s
Replace all weight-based interfaces in MBB with probability-based interfaces, and update all uses of old interfaces. (This is the second attempt to submit this patch. The first caused two assertion failures and was reverted. See https://llvm.org/bugs/show_bug.cgi?id=25687) The patch in http://reviews.llvm.org/D13745 is broken into four parts: 1. New interfaces without functional changes (http://reviews.llvm.org/D13908). 2. Use new interfaces in SelectionDAG, while in other passes treat probabilities as weights (http://reviews.llvm.org/D14361). 3. Use new interfaces in all other passes. 4. Remove old interfaces. This patch is 3+4 above. In this patch, MBB won't provide weight-based interfaces any more, which are totally replaced by probability-based ones. The interface addSuccessor() is redesigned so that the default probability is unknown. We allow unknown probabilities but don't allow using it together with known probabilities in successor list. That is to say, we either have a list of successors with all known probabilities, or all unknown probabilities. In the latter case, we assume each successor has 1/N probability where N is the number of successors. An assertion checks if the user is attempting to add a successor with the disallowed mixed use as stated above. This can help us catch many misuses. All uses of weight-based interfaces are now updated to use probability-based ones. Differential revision: http://reviews.llvm.org/D14973 llvm-svn: 254377
2015-12-01 13:29:22 +08:00
; RUN: llc < %s -mtriple thumbv7s-apple-darwin -asm-verbose=false -print-machineinstrs=if-converter 2>&1 | FileCheck --check-prefix=CHECK-PROB %s
[CodeGen][IfCvt] Don't re-ifcvt blocks with unanalyzable terminators. If we couldn't analyze its terminator (i.e., it's an indirectbr, or some other weirdness), we can't safely re-if-convert a predicated block, because we can't tell whether the predicated terminator can fallthrough (it does). Currently, we would completely ignore the fallthrough successor. In the added testcase, this means we used to generate: ... @ %entry: cmp r5, #21 ittt ne @ %cc1f: cmpne r7, #42 @ %cc2t: strne.w r5, [r8] movne pc, r10 @ %cc1t: ... Whereas the successor of %cc1f was originally %bb1. With the fix, we get the correct: ... @ %entry: cmp r5, #21 itt eq @ %cc1t: streq.w r5, [r11] moveq pc, r0 @ %cc1f: cmp r7, #42 itt ne @ %cc2t: strne.w r5, [r8] movne pc, r10 @ %bb1: ... rdar://20192768 Differential Revision: http://reviews.llvm.org/D8509 llvm-svn: 232872
2015-03-21 09:23:15 +08:00
declare i32 @foo(i32)
declare i8* @bar(i32, i8*, i8*)
; Verify that we don't try to iteratively re-ifconvert a block with a
; (predicated) indirectbr terminator.
; If we do, we would ignore its fallthrough successor.
; CHECK-LABEL: test:
; CHECK: cmp {{.*}}, #21
; CHECK-NEXT: itt eq
; CHECK-NEXT: streq.w
; CHECK-NEXT: moveq pc
; CHECK-NEXT: LBB{{[0-9_]+}}:
; CHECK-NEXT: cmp {{.*}}, #42
; CHECK-NEXT: itt ne
; CHECK-NEXT: strne.w
; CHECK-NEXT: movne pc
; CHECK-NEXT: Ltmp
; CHECK-NEXT: LBB0_2:
; CHECK-NEXT: movw r0, #1234
; CHECK-NEXT: b [[FOOCALL:LBB[0-9_]+]]
; CHECK-NEXT: Ltmp
; CHECK-NEXT: LBB{{[0-9_]+}}:
; CHECK-NEXT: movw r0, #4567
; CHECK-NEXT: [[FOOCALL]]:
; CHECK-NEXT: blx _foo
Update edge weights properly when merging blocks in if-conversion. In if-conversion, there is a utility function MergeBlocks() that is used to merge blocks. However, when new edges are built in this function the edge weight is either not provided or not updated properly, leading to a modified CFG with incorrect edge weights. This patch corrects this issue. Differential Revision: http://reviews.llvm.org/D12513 llvm-svn: 248030
2015-09-19 04:22:41 +08:00
;
Replace all weight-based interfaces in MBB with probability-based interfaces, and update all uses of old interfaces. (This is the second attempt to submit this patch. The first caused two assertion failures and was reverted. See https://llvm.org/bugs/show_bug.cgi?id=25687) The patch in http://reviews.llvm.org/D13745 is broken into four parts: 1. New interfaces without functional changes (http://reviews.llvm.org/D13908). 2. Use new interfaces in SelectionDAG, while in other passes treat probabilities as weights (http://reviews.llvm.org/D14361). 3. Use new interfaces in all other passes. 4. Remove old interfaces. This patch is 3+4 above. In this patch, MBB won't provide weight-based interfaces any more, which are totally replaced by probability-based ones. The interface addSuccessor() is redesigned so that the default probability is unknown. We allow unknown probabilities but don't allow using it together with known probabilities in successor list. That is to say, we either have a list of successors with all known probabilities, or all unknown probabilities. In the latter case, we assume each successor has 1/N probability where N is the number of successors. An assertion checks if the user is attempting to add a successor with the disallowed mixed use as stated above. This can help us catch many misuses. All uses of weight-based interfaces are now updated to use probability-based ones. Differential revision: http://reviews.llvm.org/D14973 llvm-svn: 254377
2015-12-01 13:29:22 +08:00
; CHECK-PROB: BB#0:
; CHECK-PROB: Successors according to CFG: BB#1({{[0-9a-fx/= ]+}}50.00%) BB#2({{[0-9a-fx/= ]+}}25.00%) BB#4({{[0-9a-fx/= ]+}}25.00%)
; CHECK-PROB: BB#1:
; CHECK-PROB: Successors according to CFG: BB#2({{[0-9a-fx/= ]+}}75.00%) BB#4({{[0-9a-fx/= ]+}}25.00%)
[CodeGen][IfCvt] Don't re-ifcvt blocks with unanalyzable terminators. If we couldn't analyze its terminator (i.e., it's an indirectbr, or some other weirdness), we can't safely re-if-convert a predicated block, because we can't tell whether the predicated terminator can fallthrough (it does). Currently, we would completely ignore the fallthrough successor. In the added testcase, this means we used to generate: ... @ %entry: cmp r5, #21 ittt ne @ %cc1f: cmpne r7, #42 @ %cc2t: strne.w r5, [r8] movne pc, r10 @ %cc1t: ... Whereas the successor of %cc1f was originally %bb1. With the fix, we get the correct: ... @ %entry: cmp r5, #21 itt eq @ %cc1t: streq.w r5, [r11] moveq pc, r0 @ %cc1f: cmp r7, #42 itt ne @ %cc2t: strne.w r5, [r8] movne pc, r10 @ %bb1: ... rdar://20192768 Differential Revision: http://reviews.llvm.org/D8509 llvm-svn: 232872
2015-03-21 09:23:15 +08:00
define i32 @test(i32 %a, i32 %a2, i32* %p, i32* %p2) {
entry:
%dst1 = call i8* @bar(i32 1, i8* blockaddress(@test, %bb1), i8* blockaddress(@test, %bb2))
%dst2 = call i8* @bar(i32 2, i8* blockaddress(@test, %bb1), i8* blockaddress(@test, %bb2))
%dst3 = call i8* @bar(i32 3, i8* blockaddress(@test, %bb1), i8* blockaddress(@test, %bb2))
%cc1 = icmp eq i32 %a, 21
br i1 %cc1, label %cc1t, label %cc1f
cc1t:
store i32 %a, i32* %p
indirectbr i8* %dst3, [label %bb1, label %bb2]
cc1f:
%cc2 = icmp ne i32 %a2, 42
br i1 %cc2, label %cc2t, label %bb1
cc2t:
store i32 %a, i32* %p2
indirectbr i8* %dst1, [label %bb1, label %bb2]
bb1:
%ret_bb1 = call i32 @foo(i32 1234)
ret i32 %ret_bb1
bb2:
%ret_bb2 = call i32 @foo(i32 4567)
ret i32 %ret_bb2
}