From 809d70f5b268227dbd59432dc038c74d8351be29 Mon Sep 17 00:00:00 2001 From: David Brazdil Date: Thu, 19 Nov 2015 10:29:39 +0000 Subject: ART: Fix wide stores in Optimizing SsaBuilder::VisitStoreLocal did not take into account the following: (a) when storing a wide value, the high vreg must be invalidated, (b) when storing into the high vreg of a wide value, the low vreg must be invalidated. Both situations cause overestimation of liveness but only (b) has implications on correctness. CodeGenerator::EmitEnvironment will skip the high vreg, causing deoptimizing and try/catch to load a wrong value for that vreg. In order to fix this bug, several changes had to be made to the SsaBuilder: (1) phis need to be initialized with a type which matches its inputs' size, (2) eagerly created loop header phis may end up being undefined because of their corresponding vregs being invalidated inside the loop; these are marked dead during input setting, (3) the entire SSA-building algorithm should never revive an undefined loop header phi. Bug: 25677992 Bug: https://code.google.com/p/android/issues/detail?id=194022 Change-Id: Id8a852e38c3f5ff1c2e608b1aafd6d5ac8311e32 --- compiler/optimizing/ssa_builder.h | 1 + 1 file changed, 1 insertion(+) (limited to 'compiler/optimizing/ssa_builder.h') diff --git a/compiler/optimizing/ssa_builder.h b/compiler/optimizing/ssa_builder.h index 79f1a28ac8..dcce5e4c2c 100644 --- a/compiler/optimizing/ssa_builder.h +++ b/compiler/optimizing/ssa_builder.h @@ -81,6 +81,7 @@ class SsaBuilder : public HGraphVisitor { static constexpr const char* kSsaBuilderPassName = "ssa_builder"; private: + void SetLoopHeaderPhiInputs(); void FixNullConstantType(); void EquivalentPhisCleanup(); -- cgit v1.2.3-59-g8ed1b