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llvm-project/llvm/test/Transforms/LoopSimplify/ashr-crash.ll

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Reapply r198478 "Fix PR18361: Invalidate LoopDispositions after LoopSimplify hoists things." Now with a fix for PR18384: ValueHandleBase::ValueIsDeleted. We need to invalidate SCEV's loop info when we delete a block, even if no values are hoisted. llvm-svn: 198631
2014-01-07 03:43:14 +08:00
; RUN: opt -basicaa -loop-rotate -licm -instcombine -indvars -loop-unroll -S %s | FileCheck %s
;
; PR18361: ScalarEvolution::getAddRecExpr():
; Assertion `isLoopInvariant(Operands[i],...
;
; After a series of loop optimizations, SCEV's LoopDispositions grow stale.
; In particular, LoopSimplify hoists %cmp4, resulting in this SCEV for %add:
; {(zext i1 %cmp4 to i32),+,1}<nw><%for.cond1.preheader>
;
; When recomputing the SCEV for %ashr, we truncate the operands to get:
; (zext i1 %cmp4 to i16)
;
; This SCEV was never mapped to a value so never invalidated. It's
; loop disposition is still marked as non-loop-invariant, which is
; inconsistent with the AddRec.
target datalayout = "e-i64:64-f80:128-n8:16:32:64-S128"
target triple = "x86_64-apple-macosx"
@d = common global i32 0, align 4
@a = common global i32 0, align 4
@c = common global i32 0, align 4
@b = common global i32 0, align 4
; Check that the def-use chain that leads to the bad SCEV is still
[LPM] Make LCSSA a utility with a FunctionPass that applies it to all the loops in a function, and teach LICM to work in the presance of LCSSA. Previously, LCSSA was a loop pass. That made passes requiring it also be loop passes and unable to depend on function analysis passes easily. It also caused outer loops to have a different "canonical" form from inner loops during analysis. Instead, we go into LCSSA form and preserve it through the loop pass manager run. Note that this has the same problem as LoopSimplify that prevents enabling its verification -- loop passes which run at the end of the loop pass manager and don't preserve these are valid, but the subsequent loop pass runs of outer loops that do preserve this pass trigger too much verification and fail because the inner loop no longer verifies. The other problem this exposed is that LICM was completely unable to handle LCSSA form. It didn't preserve it and it actually would give up on moving instructions in many cases when they were used by an LCSSA phi node. I've taught LICM to support detecting LCSSA-form PHI nodes and to hoist and sink around them. This may actually let LICM fire significantly more because we put everything into LCSSA form to rotate the loop before running LICM. =/ Now LICM should handle that fine and preserve it correctly. The down side is that LICM has to require LCSSA in order to preserve it. This is just a fact of life for LCSSA. It's entirely possible we should completely remove LCSSA from the optimizer. The test updates are essentially accomodating LCSSA phi nodes in the output of LICM, and the fact that we now completely sink every instruction in ashr-crash below the loop bodies prior to unrolling. With this change, LCSSA is computed only three times in the pass pipeline. One of them could be removed (and potentially a SCEV run and a separate LoopPassManager entirely!) if we had a LoopPass variant of InstCombine that ran InstCombine on the loop body but refused to combine away LCSSA PHI nodes. Currently, this also prevents loop unrolling from being in the same loop pass manager is rotate, LICM, and unswitch. There is one thing that I *really* don't like -- preserving LCSSA in LICM is quite expensive. We end up having to re-run LCSSA twice for some loops after LICM runs because LICM can undo LCSSA both in the current loop and the parent loop. I don't really see good solutions to this other than to completely move away from LCSSA and using tools like SSAUpdater instead. llvm-svn: 200067
2014-01-25 12:07:24 +08:00
; there.
Reapply r198478 "Fix PR18361: Invalidate LoopDispositions after LoopSimplify hoists things." Now with a fix for PR18384: ValueHandleBase::ValueIsDeleted. We need to invalidate SCEV's loop info when we delete a block, even if no values are hoisted. llvm-svn: 198631
2014-01-07 03:43:14 +08:00
;
; CHECK-LABEL: @foo
; CHECK-LABEL: entry:
; CHECK-LABEL: for.cond1.preheader:
; CHECK-LABEL: for.body3:
[LPM] Switch LICM to actively use LCSSA in addition to preserving it. Fixes PR18753 and PR18782. This is necessary for LICM to preserve LCSSA correctly and efficiently. There is still some active discussion about whether we should be using LCSSA, but we can't just immediately stop using it and we *need* LICM to preserve it while we are using it. We can restore the old SSAUpdater driven code if and when there is a serious effort to remove the reliance on LCSSA from all of the loop passes. However, this also serves as a great example of why LCSSA is very nice to have. This change significantly simplifies the process of sinking instructions for LICM, and makes it quite a bit less expensive. It wouldn't even be as complex as it is except that I had to start the process of removing the big recursive LCSSA formation hammer in order to switch even this much of the re-forming code to asserting that LCSSA was preserved. I'll fully remove that next just to tidy things up until the LCSSA debate settles one way or the other. llvm-svn: 201148
2014-02-11 20:52:27 +08:00
; CHECK: %cmp4.le.le
; CHECK: %conv.le.le = zext i1 %cmp4.le.le to i32
; CHECK: %xor.le.le = xor i32 %conv6.le.le, 1
Reapply r198478 "Fix PR18361: Invalidate LoopDispositions after LoopSimplify hoists things." Now with a fix for PR18384: ValueHandleBase::ValueIsDeleted. We need to invalidate SCEV's loop info when we delete a block, even if no values are hoisted. llvm-svn: 198631
2014-01-07 03:43:14 +08:00
define void @foo() {
entry:
br label %for.cond
for.cond: ; preds = %for.inc7, %entry
%storemerge = phi i32 [ 0, %entry ], [ %inc8, %for.inc7 ]
%f.0 = phi i32 [ undef, %entry ], [ %f.1, %for.inc7 ]
store i32 %storemerge, i32* @d, align 4
%cmp = icmp slt i32 %storemerge, 1
br i1 %cmp, label %for.cond1, label %for.end9
for.cond1: ; preds = %for.cond, %for.body3
%storemerge1 = phi i32 [ %inc, %for.body3 ], [ 0, %for.cond ]
%f.1 = phi i32 [ %xor, %for.body3 ], [ %f.0, %for.cond ]
store i32 %storemerge1, i32* @a, align 4
%cmp2 = icmp slt i32 %storemerge1, 1
br i1 %cmp2, label %for.body3, label %for.inc7
for.body3: ; preds = %for.cond1
[opaque pointer type] Add textual IR support for explicit type parameter to load instruction Essentially the same as the GEP change in r230786. A similar migration script can be used to update test cases, though a few more test case improvements/changes were required this time around: (r229269-r229278) import fileinput import sys import re pat = re.compile(r"((?:=|:|^)\s*load (?:atomic )?(?:volatile )?(.*?))(| addrspace\(\d+\) *)\*($| *(?:%|@|null|undef|blockaddress|getelementptr|addrspacecast|bitcast|inttoptr|\[\[[a-zA-Z]|\{\{).*$)") for line in sys.stdin: sys.stdout.write(re.sub(pat, r"\1, \2\3*\4", line)) Reviewers: rafael, dexonsmith, grosser Differential Revision: http://reviews.llvm.org/D7649 llvm-svn: 230794
2015-02-28 05:17:42 +08:00
%0 = load i32, i32* @c, align 4
Reapply r198478 "Fix PR18361: Invalidate LoopDispositions after LoopSimplify hoists things." Now with a fix for PR18384: ValueHandleBase::ValueIsDeleted. We need to invalidate SCEV's loop info when we delete a block, even if no values are hoisted. llvm-svn: 198631
2014-01-07 03:43:14 +08:00
%cmp4 = icmp sge i32 %storemerge1, %0
%conv = zext i1 %cmp4 to i32
[opaque pointer type] Add textual IR support for explicit type parameter to load instruction Essentially the same as the GEP change in r230786. A similar migration script can be used to update test cases, though a few more test case improvements/changes were required this time around: (r229269-r229278) import fileinput import sys import re pat = re.compile(r"((?:=|:|^)\s*load (?:atomic )?(?:volatile )?(.*?))(| addrspace\(\d+\) *)\*($| *(?:%|@|null|undef|blockaddress|getelementptr|addrspacecast|bitcast|inttoptr|\[\[[a-zA-Z]|\{\{).*$)") for line in sys.stdin: sys.stdout.write(re.sub(pat, r"\1, \2\3*\4", line)) Reviewers: rafael, dexonsmith, grosser Differential Revision: http://reviews.llvm.org/D7649 llvm-svn: 230794
2015-02-28 05:17:42 +08:00
%1 = load i32, i32* @d, align 4
Reapply r198478 "Fix PR18361: Invalidate LoopDispositions after LoopSimplify hoists things." Now with a fix for PR18384: ValueHandleBase::ValueIsDeleted. We need to invalidate SCEV's loop info when we delete a block, even if no values are hoisted. llvm-svn: 198631
2014-01-07 03:43:14 +08:00
%add = add nsw i32 %conv, %1
%sext = shl i32 %add, 16
%conv6 = ashr exact i32 %sext, 16
%xor = xor i32 %conv6, 1
%inc = add nsw i32 %storemerge1, 1
br label %for.cond1
for.inc7: ; preds = %for.cond1
[opaque pointer type] Add textual IR support for explicit type parameter to load instruction Essentially the same as the GEP change in r230786. A similar migration script can be used to update test cases, though a few more test case improvements/changes were required this time around: (r229269-r229278) import fileinput import sys import re pat = re.compile(r"((?:=|:|^)\s*load (?:atomic )?(?:volatile )?(.*?))(| addrspace\(\d+\) *)\*($| *(?:%|@|null|undef|blockaddress|getelementptr|addrspacecast|bitcast|inttoptr|\[\[[a-zA-Z]|\{\{).*$)") for line in sys.stdin: sys.stdout.write(re.sub(pat, r"\1, \2\3*\4", line)) Reviewers: rafael, dexonsmith, grosser Differential Revision: http://reviews.llvm.org/D7649 llvm-svn: 230794
2015-02-28 05:17:42 +08:00
%2 = load i32, i32* @d, align 4
Reapply r198478 "Fix PR18361: Invalidate LoopDispositions after LoopSimplify hoists things." Now with a fix for PR18384: ValueHandleBase::ValueIsDeleted. We need to invalidate SCEV's loop info when we delete a block, even if no values are hoisted. llvm-svn: 198631
2014-01-07 03:43:14 +08:00
%inc8 = add nsw i32 %2, 1
br label %for.cond
for.end9: ; preds = %for.cond
%cmp10 = icmp sgt i32 %f.0, 0
br i1 %cmp10, label %if.then, label %if.end
if.then: ; preds = %for.end9
store i32 0, i32* @b, align 4
br label %if.end
if.end: ; preds = %if.then, %for.end9
ret void
}