[llvm] r307729 - [IPO] Temporarily rollback r307215.
Davide Italiano via llvm-commits
llvm-commits at lists.llvm.org
Tue Jul 11 16:10:18 PDT 2017
Author: davide
Date: Tue Jul 11 16:10:17 2017
New Revision: 307729
URL: http://llvm.org/viewvc/llvm-project?rev=307729&view=rev
Log:
[IPO] Temporarily rollback r307215.
[GlobalOpt] Remove unreachable blocks before optimizing a function.
While the change is presumably correct, it exposes a latent bug
in DI which breaks on of the CFI checks. I'll analyze it further
and try to understand what's going on.
Removed:
llvm/trunk/test/Transforms/GlobalOpt/pr33686.ll
Modified:
llvm/trunk/lib/Transforms/IPO/GlobalOpt.cpp
Modified: llvm/trunk/lib/Transforms/IPO/GlobalOpt.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/IPO/GlobalOpt.cpp?rev=307729&r1=307728&r2=307729&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/IPO/GlobalOpt.cpp (original)
+++ llvm/trunk/lib/Transforms/IPO/GlobalOpt.cpp Tue Jul 11 16:10:17 2017
@@ -2026,24 +2026,6 @@ OptimizeFunctions(Module &M, TargetLibra
continue;
}
- // LLVM's definition of dominance allows instructions that are cyclic
- // in unreachable blocks, e.g.:
- // %pat = select i1 %condition, @global, i16* %pat
- // because any instruction dominates an instruction in a block that's
- // not reachable from entry.
- // So, remove unreachable blocks from the function, because a) there's
- // no point in analyzing them and b) GlobalOpt should otherwise grow
- // some more complicated logic to break these cycles.
- // Removing unreachable blocks might invalidate the dominator so we
- // recalculate it.
- if (!F->isDeclaration()) {
- if (removeUnreachableBlocks(*F)) {
- auto &DT = LookupDomTree(*F);
- DT.recalculate(*F);
- Changed = true;
- }
- }
-
Changed |= processGlobal(*F, TLI, LookupDomTree);
if (!F->hasLocalLinkage())
Removed: llvm/trunk/test/Transforms/GlobalOpt/pr33686.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/GlobalOpt/pr33686.ll?rev=307728&view=auto
==============================================================================
--- llvm/trunk/test/Transforms/GlobalOpt/pr33686.ll (original)
+++ llvm/trunk/test/Transforms/GlobalOpt/pr33686.ll (removed)
@@ -1,17 +0,0 @@
-; RUN: opt -S -globalopt %s | FileCheck %s
-
-; CHECK-LABEL: define void @beth
-; CHECK-NEXT: entry:
-; CHECK-NEXT: ret void
-; CHEC-NEXT: }
-
- at glob = external global i16, align 1
-
-define void @beth() {
-entry:
- ret void
-
-notreachable:
- %patatino = select i1 undef, i16* @glob, i16* %patatino
- br label %notreachable
-}
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