From d5bd8eeafe60aa50ebe365f80e302f578ea96a35 Mon Sep 17 00:00:00 2001 From: Hans Wennborg Date: Wed, 6 Dec 2017 01:47:55 +0000 Subject: [PATCH] Revert r319482 and r319483 "[memcpyopt] Teach memcpyopt to optimize across basic blocks" This caused PR35519. > [memcpyopt] Teach memcpyopt to optimize across basic blocks > > This teaches memcpyopt to make a non-local memdep query when a local query > indicates that the dependency is non-local. This notably allows it to > eliminate many more llvm.memcpy calls in common Rust code, often by 20-30%. > > Fixes PR28958. > > Differential Revision: https://reviews.llvm.org/D38374 > > [memcpyopt] Commit file missed in r319482. > > This change was meant to be included with r319482 but was accidentally > omitted. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@319873 91177308-0d34-0410-b5e6-96231b3b80d8 --- .../llvm/Analysis/MemoryDependenceAnalysis.h | 6 - lib/Analysis/MemoryDependenceAnalysis.cpp | 8 -- lib/Transforms/Scalar/MemCpyOptimizer.cpp | 31 +---- .../MemCpyOpt/memcpy-invoke-memcpy.ll | 48 -------- .../MemCpyOpt/nonlocal-memcpy-memcpy.ll | 114 ------------------ 5 files changed, 3 insertions(+), 204 deletions(-) delete mode 100644 test/Transforms/MemCpyOpt/memcpy-invoke-memcpy.ll delete mode 100644 test/Transforms/MemCpyOpt/nonlocal-memcpy-memcpy.ll diff --git a/include/llvm/Analysis/MemoryDependenceAnalysis.h b/include/llvm/Analysis/MemoryDependenceAnalysis.h index 391a333594e..c2974525a6f 100644 --- a/include/llvm/Analysis/MemoryDependenceAnalysis.h +++ b/include/llvm/Analysis/MemoryDependenceAnalysis.h @@ -407,12 +407,6 @@ public: void getNonLocalPointerDependency(Instruction *QueryInst, SmallVectorImpl &Result); - /// Perform a dependency query specifically for QueryInst's access to Loc. - /// The other comments for getNonLocalPointerDependency apply here as well. - void getNonLocalPointerDependencyFrom(Instruction *QueryInst, - const MemoryLocation &Loc, bool isLoad, - SmallVectorImpl &Result); - /// Removes an instruction from the dependence analysis, updating the /// dependence of instructions that previously depended on it. void removeInstruction(Instruction *InstToRemove); diff --git a/lib/Analysis/MemoryDependenceAnalysis.cpp b/lib/Analysis/MemoryDependenceAnalysis.cpp index c54f676eb94..57d04af0470 100644 --- a/lib/Analysis/MemoryDependenceAnalysis.cpp +++ b/lib/Analysis/MemoryDependenceAnalysis.cpp @@ -917,14 +917,6 @@ void MemoryDependenceResults::getNonLocalPointerDependency( Instruction *QueryInst, SmallVectorImpl &Result) { const MemoryLocation Loc = MemoryLocation::get(QueryInst); bool isLoad = isa(QueryInst); - return getNonLocalPointerDependencyFrom(QueryInst, Loc, isLoad, Result); -} - -void MemoryDependenceResults::getNonLocalPointerDependencyFrom( - Instruction *QueryInst, - const MemoryLocation &Loc, - bool isLoad, - SmallVectorImpl &Result) { BasicBlock *FromBB = QueryInst->getParent(); assert(FromBB); diff --git a/lib/Transforms/Scalar/MemCpyOptimizer.cpp b/lib/Transforms/Scalar/MemCpyOptimizer.cpp index cd3e4ba88bc..9c870b42a74 100644 --- a/lib/Transforms/Scalar/MemCpyOptimizer.cpp +++ b/lib/Transforms/Scalar/MemCpyOptimizer.cpp @@ -1031,22 +1031,9 @@ bool MemCpyOptPass::processMemCpyMemCpyDependence(MemCpyInst *M, // // NOTE: This is conservative, it will stop on any read from the source loc, // not just the defining memcpy. - MemoryLocation SourceLoc = MemoryLocation::getForSource(MDep); - MemDepResult SourceDep = MD->getPointerDependencyFrom(SourceLoc, false, - M->getIterator(), M->getParent()); - - if (SourceDep.isNonLocal()) { - SmallVector NonLocalDepResults; - MD->getNonLocalPointerDependencyFrom(M, SourceLoc, /*isLoad=*/false, - NonLocalDepResults); - if (NonLocalDepResults.size() == 1) { - SourceDep = NonLocalDepResults[0].getResult(); - assert((!SourceDep.getInst() || - LookupDomTree().dominates(SourceDep.getInst(), M)) && - "when memdep returns exactly one result, it should dominate"); - } - } - + MemDepResult SourceDep = + MD->getPointerDependencyFrom(MemoryLocation::getForSource(MDep), false, + M->getIterator(), M->getParent()); if (!SourceDep.isClobber() || SourceDep.getInst() != MDep) return false; @@ -1248,18 +1235,6 @@ bool MemCpyOptPass::processMemCpy(MemCpyInst *M) { MemDepResult SrcDepInfo = MD->getPointerDependencyFrom( SrcLoc, true, M->getIterator(), M->getParent()); - if (SrcDepInfo.isNonLocal()) { - SmallVector NonLocalDepResults; - MD->getNonLocalPointerDependencyFrom(M, SrcLoc, /*isLoad=*/true, - NonLocalDepResults); - if (NonLocalDepResults.size() == 1) { - SrcDepInfo = NonLocalDepResults[0].getResult(); - assert((!SrcDepInfo.getInst() || - LookupDomTree().dominates(SrcDepInfo.getInst(), M)) && - "when memdep returns exactly one result, it should dominate"); - } - } - if (SrcDepInfo.isClobber()) { if (MemCpyInst *MDep = dyn_cast(SrcDepInfo.getInst())) return processMemCpyMemCpyDependence(M, MDep); diff --git a/test/Transforms/MemCpyOpt/memcpy-invoke-memcpy.ll b/test/Transforms/MemCpyOpt/memcpy-invoke-memcpy.ll deleted file mode 100644 index e3d1f6dd2b1..00000000000 --- a/test/Transforms/MemCpyOpt/memcpy-invoke-memcpy.ll +++ /dev/null @@ -1,48 +0,0 @@ -; RUN: opt < %s -memcpyopt -S | FileCheck %s -; Test memcpy-memcpy dependencies across invoke edges. - -; Test that memcpyopt works across the non-unwind edge of an invoke. - -define hidden void @test_normal(i8* noalias %dst, i8* %src) personality i8* bitcast (i32 (...)* @__gxx_personality_v0 to i8*) { -entry: - %temp = alloca i8, i32 64 - call void @llvm.memcpy.p0i8.p0i8.i64(i8* %temp, i8* nonnull %src, i64 64, i32 8, i1 false) -; CHECK: call void @llvm.memcpy.p0i8.p0i8.i64(i8* %temp, i8* nonnull %src, i64 64, i32 8, i1 false) - invoke void @invoke_me() - to label %try.cont unwind label %lpad - -lpad: - landingpad { i8*, i32 } - catch i8* null - ret void - -try.cont: - call void @llvm.memcpy.p0i8.p0i8.i64(i8* %dst, i8* %temp, i64 64, i32 8, i1 false) -; CHECK: call void @llvm.memcpy.p0i8.p0i8.i64(i8* %dst, i8* %src, i64 64, i32 8, i1 false) - ret void -} - -; Test that memcpyopt works across the unwind edge of an invoke. - -define hidden void @test_unwind(i8* noalias %dst, i8* %src) personality i8* bitcast (i32 (...)* @__gxx_personality_v0 to i8*) { -entry: - %temp = alloca i8, i32 64 - call void @llvm.memcpy.p0i8.p0i8.i64(i8* %temp, i8* nonnull %src, i64 64, i32 8, i1 false) -; CHECK: call void @llvm.memcpy.p0i8.p0i8.i64(i8* %temp, i8* nonnull %src, i64 64, i32 8, i1 false) - invoke void @invoke_me() - to label %try.cont unwind label %lpad - -lpad: - landingpad { i8*, i32 } - catch i8* null - call void @llvm.memcpy.p0i8.p0i8.i64(i8* %dst, i8* %temp, i64 64, i32 8, i1 false) -; CHECK: call void @llvm.memcpy.p0i8.p0i8.i64(i8* %dst, i8* %src, i64 64, i32 8, i1 false) - ret void - -try.cont: - ret void -} - -declare void @llvm.memcpy.p0i8.p0i8.i64(i8* nocapture writeonly, i8* nocapture readonly, i64, i32, i1) -declare i32 @__gxx_personality_v0(...) -declare void @invoke_me() readnone diff --git a/test/Transforms/MemCpyOpt/nonlocal-memcpy-memcpy.ll b/test/Transforms/MemCpyOpt/nonlocal-memcpy-memcpy.ll deleted file mode 100644 index 5b0510211d9..00000000000 --- a/test/Transforms/MemCpyOpt/nonlocal-memcpy-memcpy.ll +++ /dev/null @@ -1,114 +0,0 @@ -; RUN: opt < %s -memcpyopt -S | FileCheck %s -; Make sure memcpy-memcpy dependence is optimized across -; basic blocks (conditional branches and invokes). - -%struct.s = type { i32, i32 } - -@s_foo = private unnamed_addr constant %struct.s { i32 1, i32 2 }, align 4 -@s_baz = private unnamed_addr constant %struct.s { i32 1, i32 2 }, align 4 -@i = external constant i8* - -declare void @qux() -declare void @llvm.memcpy.p0i8.p0i8.i64(i8* nocapture writeonly, i8* nocapture readonly, i64, i32, i1) -declare void @__cxa_throw(i8*, i8*, i8*) -declare i32 @__gxx_personality_v0(...) -declare i8* @__cxa_begin_catch(i8*) - -; A simple partial redundancy. Test that the second memcpy is optimized -; to copy directly from the original source rather than from the temporary. - -; CHECK-LABEL: @wobble -define void @wobble(i8* noalias %dst, i8* %src, i1 %some_condition) { -bb: - %temp = alloca i8, i32 64 - call void @llvm.memcpy.p0i8.p0i8.i64(i8* %temp, i8* nonnull %src, i64 64, i32 8, i1 false) -; CHECK: call void @llvm.memcpy.p0i8.p0i8.i64(i8* %temp, i8* nonnull %src, i64 64, i32 8, i1 false) - br i1 %some_condition, label %more, label %out - -out: - call void @qux() - unreachable - -more: - call void @llvm.memcpy.p0i8.p0i8.i64(i8* %dst, i8* %temp, i64 64, i32 8, i1 false) -; CHECK: call void @llvm.memcpy.p0i8.p0i8.i64(i8* %dst, i8* %src, i64 64, i32 8, i1 false) - ret void -} - -; A CFG triangle with a partial redundancy targeting an alloca. Test that the -; memcpy inside the triangle is optimized to copy directly from the original -; source rather than from the temporary. - -; CHECK-LABEL: @foo -define i32 @foo(i1 %t3) { -bb: - %s = alloca %struct.s, align 4 - %t = alloca %struct.s, align 4 - %s1 = bitcast %struct.s* %s to i8* - call void @llvm.memcpy.p0i8.p0i8.i64(i8* %s1, i8* bitcast (%struct.s* @s_foo to i8*), i64 8, i32 4, i1 false) -; CHECK: call void @llvm.memcpy.p0i8.p0i8.i64(i8* %s1, i8* bitcast (%struct.s* @s_foo to i8*), i64 8, i32 4, i1 false) - br i1 %t3, label %bb4, label %bb7 - -bb4: ; preds = %bb - %t5 = bitcast %struct.s* %t to i8* - %s6 = bitcast %struct.s* %s to i8* - call void @llvm.memcpy.p0i8.p0i8.i64(i8* %t5, i8* %s6, i64 8, i32 4, i1 false) -; CHECK: call void @llvm.memcpy.p0i8.p0i8.i64(i8* %t5, i8* bitcast (%struct.s* @s_foo to i8*), i64 8, i32 4, i1 false) - br label %bb7 - -bb7: ; preds = %bb4, %bb - %t8 = getelementptr %struct.s, %struct.s* %t, i32 0, i32 0 - %t9 = load i32, i32* %t8, align 4 - %t10 = getelementptr %struct.s, %struct.s* %t, i32 0, i32 1 - %t11 = load i32, i32* %t10, align 4 - %t12 = add i32 %t9, %t11 - ret i32 %t12 -} - -; A CFG diamond with an invoke on one side, and a partially redundant memcpy -; into an alloca on the other. Test that the memcpy inside the diamond is -; optimized to copy ; directly from the original source rather than from the -; temporary. This more complex test represents a relatively common usage -; pattern. - -; CHECK-LABEL: @baz -define i32 @baz(i1 %t5) personality i8* bitcast (i32 (...)* @__gxx_personality_v0 to i8*) { -bb: - %s = alloca %struct.s, align 4 - %t = alloca %struct.s, align 4 - %s3 = bitcast %struct.s* %s to i8* - call void @llvm.memcpy.p0i8.p0i8.i64(i8* %s3, i8* bitcast (%struct.s* @s_baz to i8*), i64 8, i32 4, i1 false) -; CHECK: call void @llvm.memcpy.p0i8.p0i8.i64(i8* %s3, i8* bitcast (%struct.s* @s_baz to i8*), i64 8, i32 4, i1 false) - br i1 %t5, label %bb6, label %bb22 - -bb6: ; preds = %bb - invoke void @__cxa_throw(i8* null, i8* bitcast (i8** @i to i8*), i8* null) - to label %bb25 unwind label %bb9 - -bb9: ; preds = %bb6 - %t10 = landingpad { i8*, i32 } - catch i8* null - br label %bb13 - -bb13: ; preds = %bb9 - %t15 = call i8* @__cxa_begin_catch(i8* null) - br label %bb23 - -bb22: ; preds = %bb - %t23 = bitcast %struct.s* %t to i8* - %s24 = bitcast %struct.s* %s to i8* - call void @llvm.memcpy.p0i8.p0i8.i64(i8* %t23, i8* %s24, i64 8, i32 4, i1 false) -; CHECK: call void @llvm.memcpy.p0i8.p0i8.i64(i8* %t23, i8* bitcast (%struct.s* @s_baz to i8*), i64 8, i32 4, i1 false) - br label %bb23 - -bb23: ; preds = %bb22, %bb13 - %t17 = getelementptr inbounds %struct.s, %struct.s* %t, i32 0, i32 0 - %t18 = load i32, i32* %t17, align 4 - %t19 = getelementptr inbounds %struct.s, %struct.s* %t, i32 0, i32 1 - %t20 = load i32, i32* %t19, align 4 - %t21 = add nsw i32 %t18, %t20 - ret i32 %t21 - -bb25: ; preds = %bb6 - unreachable -} -- 2.50.1