[llvm] ec1f6f7 - Revert "[LAA] Support pointer phis in loop by analyzing each incoming pointer."
Florian Hahn via llvm-commits
llvm-commits at lists.llvm.org
Fri May 28 02:44:48 PDT 2021
Author: Florian Hahn
Date: 2021-05-28T10:33:52+01:00
New Revision: ec1f6f7e3f92d806d0f7e4d687173a150102ec5d
URL: https://github.com/llvm/llvm-project/commit/ec1f6f7e3f92d806d0f7e4d687173a150102ec5d
DIFF: https://github.com/llvm/llvm-project/commit/ec1f6f7e3f92d806d0f7e4d687173a150102ec5d.diff
LOG: Revert "[LAA] Support pointer phis in loop by analyzing each incoming pointer."
This reverts commit 1ed7f8ede564c3b11da4fdca30c36ccbff422576.
This change can cause loop-distribute to crash in some cases. Revert
until I have more time to wrap up a fix.
See PR50296, PR5028 and D102266.
Added:
Modified:
llvm/lib/Analysis/LoopAccessAnalysis.cpp
llvm/test/Analysis/LoopAccessAnalysis/pointer-phis.ll
llvm/test/Transforms/LoopVectorize/vectorize-pointer-phis.ll
Removed:
################################################################################
diff --git a/llvm/lib/Analysis/LoopAccessAnalysis.cpp b/llvm/lib/Analysis/LoopAccessAnalysis.cpp
index 35350582b4b5..3248b2a2ac6b 100644
--- a/llvm/lib/Analysis/LoopAccessAnalysis.cpp
+++ b/llvm/lib/Analysis/LoopAccessAnalysis.cpp
@@ -1938,18 +1938,7 @@ void LoopAccessInfo::analyzeLoop(AAResults *AA, LoopInfo *LI,
if (blockNeedsPredication(ST->getParent(), TheLoop, DT))
Loc.AATags.TBAA = nullptr;
- // SCEV does not look through non-header PHIs inside the loop. Such phis
- // can be analyzed by adding separate accesses for each incoming pointer
- // value.
- auto *PN = dyn_cast<PHINode>(Loc.Ptr);
- if (PN && TheLoop->contains(PN->getParent()) &&
- PN->getParent() != TheLoop->getHeader()) {
- for (const Use &Inc : PN->incoming_values()) {
- MemoryLocation NewLoc = Loc.getWithNewPtr(Inc);
- Accesses.addStore(NewLoc);
- }
- } else
- Accesses.addStore(Loc);
+ Accesses.addStore(Loc);
}
}
@@ -1993,17 +1982,7 @@ void LoopAccessInfo::analyzeLoop(AAResults *AA, LoopInfo *LI,
if (blockNeedsPredication(LD->getParent(), TheLoop, DT))
Loc.AATags.TBAA = nullptr;
- // SCEV does not look through non-header PHIs inside the loop. Such phis can
- // be analyzed by adding separate accesses for each incoming pointer value.
- auto *PN = dyn_cast<PHINode>(Loc.Ptr);
- if (PN && TheLoop->contains(PN->getParent()) &&
- PN->getParent() != TheLoop->getHeader()) {
- for (const Use &Inc : PN->incoming_values()) {
- MemoryLocation NewLoc = Loc.getWithNewPtr(Inc);
- Accesses.addLoad(NewLoc, IsReadOnlyPtr);
- }
- } else
- Accesses.addLoad(Loc, IsReadOnlyPtr);
+ Accesses.addLoad(Loc, IsReadOnlyPtr);
}
// If we write (or read-write) to a single destination and there are no
diff --git a/llvm/test/Analysis/LoopAccessAnalysis/pointer-phis.ll b/llvm/test/Analysis/LoopAccessAnalysis/pointer-phis.ll
index dcdf6dd6a1fc..c803825896e9 100644
--- a/llvm/test/Analysis/LoopAccessAnalysis/pointer-phis.ll
+++ b/llvm/test/Analysis/LoopAccessAnalysis/pointer-phis.ll
@@ -6,7 +6,7 @@
define i32 @load_with_pointer_phi_no_runtime_checks(%s1* %data) {
; CHECK-LABEL: load_with_pointer_phi_no_runtime_checks
; CHECK-NEXT: loop.header:
-; CHECK-NEXT: Memory dependences are safe
+; CHECK-NEXT: Report: cannot identify array bounds
;
entry:
br label %loop.header
@@ -41,7 +41,7 @@ exit: ; preds = %loop.latch
define i32 @store_with_pointer_phi_no_runtime_checks(%s1* %data) {
; CHECK-LABEL: 'store_with_pointer_phi_no_runtime_checks'
; CHECK-NEXT: loop.header:
-; CHECK-NEXT: Memory dependences are safe
+; CHECK-NEXT: Report: cannot identify array bounds
;
entry:
br label %loop.header
@@ -76,23 +76,7 @@ exit: ; preds = %loop.latch
define i32 @store_with_pointer_phi_runtime_checks(double* %A, double* %B, double* %C) {
; CHECK-LABEL: 'store_with_pointer_phi_runtime_checks'
; CHECK-NEXT: loop.header:
-; CHECK-NEXT: Memory dependences are safe with run-time checks
-; CHECK: Run-time memory checks:
-; CHECK-NEXT: Check 0:
-; CHECK-NEXT: Comparing group ([[GROUP_C:.+]]):
-; CHECK-NEXT: %gep.2 = getelementptr inbounds double, double* %C, i64 %iv
-; CHECK-NEXT: Against group ([[GROUP_B:.+]]):
-; CHECK-NEXT: %gep.1 = getelementptr inbounds double, double* %B, i64 %iv
-; CHECK-NEXT: Check 1:
-; CHECK-NEXT: Comparing group ([[GROUP_C]]):
-; CHECK-NEXT: %gep.2 = getelementptr inbounds double, double* %C, i64 %iv
-; CHECK-NEXT: Against group ([[GROUP_A:.+]]):
-; CHECK-NEXT: %arrayidx = getelementptr inbounds double, double* %A, i64 %iv
-; CHECK-NEXT: Check 2:
-; CHECK-NEXT: Comparing group ([[GROUP_B]]):
-; CHECK-NEXT: %gep.1 = getelementptr inbounds double, double* %B, i64 %iv
-; CHECK-NEXT: Against group ([[GROUP_A]]):
-; CHECK-NEXT: %arrayidx = getelementptr inbounds double, double* %A, i64 %iv
+; CHECK-NEXT: Report: cannot identify array bounds
;
entry:
br label %loop.header
diff --git a/llvm/test/Transforms/LoopVectorize/vectorize-pointer-phis.ll b/llvm/test/Transforms/LoopVectorize/vectorize-pointer-phis.ll
index e3168d5b5d35..53437e3d8c57 100644
--- a/llvm/test/Transforms/LoopVectorize/vectorize-pointer-phis.ll
+++ b/llvm/test/Transforms/LoopVectorize/vectorize-pointer-phis.ll
@@ -4,8 +4,7 @@
define i32 @load_with_pointer_phi_no_runtime_checks(%s1* %data) {
; CHECK-LABEL: @load_with_pointer_phi_no_runtime_checks
-; CHECK-NOT: memcheck
-; CHECK: vector.body:
+; CHECK-NOT: vector.body
;
entry:
br label %loop.header
@@ -39,8 +38,7 @@ exit: ; preds = %loop.latch
define i32 @store_with_pointer_phi_no_runtime_checks(%s1* %data) {
; CHECK-LABEL: @store_with_pointer_phi_no_runtime_checks
-; CHECK-NOT: memcheck
-; CHECK: vector.body
+; CHECK-NOT: vector.body
;
entry:
br label %loop.header
@@ -74,8 +72,7 @@ exit: ; preds = %loop.latch
define i32 @store_with_pointer_phi_runtime_checks(double* %A, double* %B, double* %C) {
; CHECK-LABEL: @store_with_pointer_phi_runtime_checks
-; CHECK: memcheck
-; CHECK: vector.body
+; CHECK-NOT: vector.body
;
entry:
br label %loop.header
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