Arnold Schwaighofer dd8c386432 SimplifyCFG: Don't convert phis into selects if we could remove undef behavior ... instead We used to transform this: define void @test6(i1 %cond, i8* %ptr) { entry: br i1 %cond, label %bb1, label %bb2 bb1: br label %bb2 bb2: %ptr.2 = phi i8* [ %ptr, %entry ], [ null, %bb1 ] store i8 2, i8* %ptr.2, align 8 ret void } into this: define void @test6(i1 %cond, i8* %ptr) { %ptr.2 = select i1 %cond, i8* null, i8* %ptr store i8 2, i8* %ptr.2, align 8 ret void } because the simplifycfg transformation into selects would happen to happen before the simplifycfg transformation that removes unreachable control flow (We have 'unreachable control flow' due to the store to null which is undefined behavior). The existing transformation that removes unreachable control flow in simplifycfg is: /// If BB has an incoming value that will always trigger undefined behavior /// (eg. null pointer dereference), remove the branch leading here. static bool removeUndefIntroducingPredecessor(BasicBlock *BB) Now we generate: define void @test6(i1 %cond, i8* %ptr) { store i8 2, i8* %ptr.2, align 8 ret void } I did not see any impact on the test-suite + externals. rdar://18596215 git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@219462 91177308-0d34-0410-b5e6-96231b3b80d8		2014-10-10 01:27:02 +00:00
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Hello
InstCombine	[InstCombine] Fix wrong folding of constant comparisons involving ashr and negative values.	2014-10-09 12:41:49 +00:00
Instrumentation	Use triple's isiOS() and isOSDarwin() methods.	2014-10-09 05:43:30 +00:00
IPO	Inliner: Non-local functions in COMDATs shouldn't be dropped	2014-10-08 19:32:32 +00:00
ObjCARC
Scalar	[Reassociate] Don't canonicalize X - undef to X + (-undef).	2014-10-09 20:06:29 +00:00
Utils	SimplifyCFG: Don't convert phis into selects if we could remove undef behavior	2014-10-10 01:27:02 +00:00
Vectorize
CMakeLists.txt
LLVMBuild.txt
Makefile