[llvm] r335965 - Fix overconfident assert in ScalarEvolution::isImpliedViaMerge
Roman Shirokiy via llvm-commits
llvm-commits at lists.llvm.org
Fri Jun 29 04:46:30 PDT 2018
Author: roman.shirokiy
Date: Fri Jun 29 04:46:30 2018
New Revision: 335965
URL: http://llvm.org/viewvc/llvm-project?rev=335965&view=rev
Log:
Fix overconfident assert in ScalarEvolution::isImpliedViaMerge
We can have AddRec with loops having many predecessors.
This changes an assert to an early return.
Differential Revision: https://reviews.llvm.org/D48766
Added:
llvm/trunk/test/Analysis/ScalarEvolution/merge-add-rec-many-inputs.ll
Modified:
llvm/trunk/lib/Analysis/ScalarEvolution.cpp
Modified: llvm/trunk/lib/Analysis/ScalarEvolution.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Analysis/ScalarEvolution.cpp?rev=335965&r1=335964&r2=335965&view=diff
==============================================================================
--- llvm/trunk/lib/Analysis/ScalarEvolution.cpp (original)
+++ llvm/trunk/lib/Analysis/ScalarEvolution.cpp Fri Jun 29 04:46:30 2018
@@ -9712,8 +9712,9 @@ bool ScalarEvolution::isImpliedViaMerge(
// AddRec. It means that there is a loop which has both AddRec and Unknown
// PHIs, for it we can compare incoming values of AddRec from above the loop
// and latch with their respective incoming values of LPhi.
- assert(LPhi->getNumIncomingValues() == 2 &&
- "Phi node standing in loop header does not have exactly 2 inputs?");
+ // TODO: Generalize to handle loops with many inputs in a header.
+ if (LPhi->getNumIncomingValues() != 2) return false;
+
auto *RLoop = RAR->getLoop();
auto *Predecessor = RLoop->getLoopPredecessor();
assert(Predecessor && "Loop with AddRec with no predecessor?");
Added: llvm/trunk/test/Analysis/ScalarEvolution/merge-add-rec-many-inputs.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Analysis/ScalarEvolution/merge-add-rec-many-inputs.ll?rev=335965&view=auto
==============================================================================
--- llvm/trunk/test/Analysis/ScalarEvolution/merge-add-rec-many-inputs.ll (added)
+++ llvm/trunk/test/Analysis/ScalarEvolution/merge-add-rec-many-inputs.ll Fri Jun 29 04:46:30 2018
@@ -0,0 +1,127 @@
+; RUN: opt < %s -analyze -scalar-evolution | FileCheck %s
+
+; Check that isImpliedViaMerge wouldn't crash when trying to prove
+; SCEVUnknown and AddRec with phi having many inputs
+; CHECK: @foo
+
+define void @foo(i1 %cond) {
+osr.type.merge79:
+ br label %bci_329
+
+bci_329: ; preds = %bci_337, %bci_326, %osr.type.merge79
+ %local_7_ = phi i32 [ 0, %osr.type.merge79 ], [ %local_7_113, %bci_326 ], [ %local_7_, %bci_337 ]
+ br i1 %cond, label %bci_360, label %bci_337
+
+bci_360: ; preds = %bci_329
+ %0 = phi i32 [ %local_7_, %bci_329 ]
+ %1 = icmp sge i32 %0, 451
+ br i1 %1, label %bci_371, label %bci_326
+
+bci_371: ; preds = %bci_304, %bci_360
+ %local_2_132 = phi i32 [ 0, %bci_360 ], [ %local_2_188, %bci_304 ]
+ %local_7_137 = phi i32 [ 0, %bci_360 ], [ %local_7_217, %bci_304 ]
+ %local_8_138 = phi i32 [ 0, %bci_360 ], [ %local_8_194, %bci_304 ]
+ %local_11_141 = phi i32 [ 0, %bci_360 ], [ %local_11_197, %bci_304 ]
+ %2 = phi i1 [ %1, %bci_360 ], [ false, %bci_304 ]
+ br i1 %2, label %bci_562, label %never_deopt
+
+bci_562: ; preds = %done437, %done405, %done395, %bci_407, %not_zero322, %bci_221, %bci_371
+ %local_2_164 = phi i32 [ %local_2_132, %bci_371 ], [ %9, %not_zero322 ], [ %local_2_188, %bci_407 ], [ %result396, %done395 ], [ %local_2_188, %bci_221 ], [ %local_2_188, %done405 ], [ %local_2_188, %done437 ]
+ %local_7_169 = phi i32 [ %local_7_137, %bci_371 ], [ %local_7_217, %not_zero322 ], [ %local_7_217, %bci_407 ], [ %local_7_217, %done395 ], [ %local_7_217, %bci_221 ], [ %local_7_217, %done405 ], [ %local_7_217, %done437 ]
+ %local_8_170 = phi i32 [ %local_8_138, %bci_371 ], [ %local_8_194, %not_zero322 ], [ %local_8_194, %bci_407 ], [ %local_8_194, %done395 ], [ %local_8_194, %bci_221 ], [ %local_8_194, %done405 ], [ %local_8_194, %done437 ]
+ %local_11_173 = phi i32 [ %local_11_141, %bci_371 ], [ %local_11_197, %not_zero322 ], [ %local_11_197, %bci_407 ], [ %local_11_197, %done395 ], [ %local_11_197, %bci_221 ], [ %local_11_197, %done405 ], [ %local_11_197, %done437 ]
+ br label %bci_604
+
+bci_604: ; preds = %not_subtype, %bci_565, %bci_562
+ %local_2_188 = phi i32 [ %local_2_164, %bci_562 ], [ %9, %bci_565 ], [ %9, %not_subtype ]
+ %local_7_193 = phi i32 [ %local_7_169, %bci_562 ], [ %local_7_217, %bci_565 ], [ %local_7_217, %not_subtype ]
+ %local_8_194 = phi i32 [ %local_8_170, %bci_562 ], [ %local_8_194, %bci_565 ], [ %local_8_194, %not_subtype ]
+ %local_11_197 = phi i32 [ %local_11_173, %bci_562 ], [ %local_11_197, %bci_565 ], [ %local_11_197, %not_subtype ]
+ %3 = add i32 1, %local_7_193
+ br label %bci_199
+
+bci_199: ; preds = %bci_591, %bci_604
+ %local_7_217 = phi i32 [ %3, %bci_604 ], [ %6, %bci_591 ]
+ %4 = mul i32 %local_2_188, %local_8_194
+ %5 = icmp sge i32 %local_7_217, %4
+ br i1 %5, label %bci_610, label %bci_216
+
+bci_610: ; preds = %bci_199
+ ret void
+
+bci_216: ; preds = %bci_199
+ br i1 %cond, label %bci_591, label %bci_221
+
+bci_591: ; preds = %bci_216
+ %6 = add i32 1, %local_7_217
+ br label %bci_199
+
+bci_221: ; preds = %bci_216
+ %7 = srem i32 %local_7_217, 6
+ %8 = add i32 %7, 114
+ switch i32 %8, label %done405 [
+ i32 114, label %bci_562
+ i32 116, label %bci_304
+ i32 117, label %bci_395
+ i32 118, label %bci_407
+ i32 119, label %bci_419
+ ]
+
+bci_419: ; preds = %bci_221
+ %9 = sub i32 %local_2_188, %local_11_197
+ br label %bci_435
+
+bci_435: ; preds = %not_zero322, %bci_419
+ br i1 %cond, label %not_zero265, label %never_deopt
+
+not_zero265: ; preds = %bci_435
+ br i1 %cond, label %in_bounds, label %out_of_bounds
+
+in_bounds: ; preds = %not_zero265
+ br i1 %cond, label %not_zero322, label %never_deopt
+
+not_zero322: ; preds = %in_bounds
+ br i1 %cond, label %bci_562, label %bci_435
+
+bci_407: ; preds = %bci_221
+ br label %bci_562
+
+bci_395: ; preds = %bci_221
+ br i1 %cond, label %done395, label %general_case394
+
+general_case394: ; preds = %bci_395
+ %10 = srem i32 %local_2_188, 0
+ br label %done395
+
+done395: ; preds = %general_case394, %bci_395
+ %result396 = phi i32 [ %10, %general_case394 ], [ 0, %bci_395 ]
+ br label %bci_562
+
+bci_304: ; preds = %bci_221
+ br i1 %cond, label %bci_371, label %bci_326
+
+done405: ; preds = %bci_221
+ br i1 %cond, label %bci_562, label %done437
+
+done437: ; preds = %done405
+ br label %bci_562
+
+bci_326: ; preds = %bci_304, %bci_360
+ %local_7_113 = phi i32 [ %local_7_, %bci_360 ], [ %local_7_217, %bci_304 ]
+ br label %bci_329
+
+bci_337: ; preds = %bci_329
+ br label %bci_329
+
+never_deopt: ; preds = %in_bounds, %bci_435, %bci_371
+ ret void
+
+out_of_bounds: ; preds = %not_zero265
+ br i1 %cond, label %bci_565, label %not_subtype
+
+bci_565: ; preds = %out_of_bounds
+ br label %bci_604
+
+not_subtype: ; preds = %out_of_bounds
+ br label %bci_604
+}
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