From 80e8b506b8134d63dc3cb6211cccc34be4b19d40 Mon Sep 17 00:00:00 2001 From: Chris Lattner Date: Sat, 19 Feb 2011 19:56:44 +0000 Subject: [PATCH] rewrite the memset_pattern pattern generation stuff to accept any 2/4/8/16-byte constant, including globals. This makes us generate much more "pretty" pattern globals as well because it doesn't break it down to an array of bytes all the time. This enables us to handle stores of relocatable globals. This kicks in about 48 times in 254.gap, giving us stuff like this: @.memset_pattern40 = internal constant [2 x %struct.TypHeader* (%struct.TypHeader*, %struct.TypHeader*)*] [%struct.TypHeader* (%struct.TypHeader*, %struct .TypHeader*)* @IsFalse, %struct.TypHeader* (%struct.TypHeader*, %struct.TypHeader*)* @IsFalse], align 16 ... call void @memset_pattern16(i8* %scevgep5859, i8* bitcast ([2 x %struct.TypHeader* (%struct.TypHeader*, %struct.TypHeader*)*]* @.memset_pattern40 to i8* ), i64 %tmp75) nounwind git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@126044 91177308-0d34-0410-b5e6-96231b3b80d8 --- lib/Transforms/Scalar/LoopIdiomRecognize.cpp | 44 ++++++-------------- test/Transforms/LoopIdiom/basic.ll | 29 ++++++++++++- 2 files changed, 39 insertions(+), 34 deletions(-) diff --git a/lib/Transforms/Scalar/LoopIdiomRecognize.cpp b/lib/Transforms/Scalar/LoopIdiomRecognize.cpp index be3ff9258fc..d7fa149492b 100644 --- a/lib/Transforms/Scalar/LoopIdiomRecognize.cpp +++ b/lib/Transforms/Scalar/LoopIdiomRecognize.cpp @@ -388,43 +388,24 @@ static Constant *getMemSetPatternValue(Value *V, const TargetData &TD) { if (Size == 0 || (Size & 7) || (Size & (Size-1))) return 0; - // Convert the constant to an integer type of the appropriate size so we can - // start hacking on it. - if (isa(V->getType())) - C = ConstantExpr::getPtrToInt(C, IntegerType::get(C->getContext(), Size)); - else if (isa(V->getType()) || V->getType()->isFloatingPointTy()) - C = ConstantExpr::getBitCast(C, IntegerType::get(C->getContext(), Size)); - else if (!isa(V->getType())) - return 0; // Unhandled type. + // Don't care enough about darwin/ppc to implement this. + if (TD.isBigEndian()) + return 0; // Convert to size in bytes. Size /= 8; - - // If we couldn't fold this to an integer, we fail. We don't bother to handle - // relocatable expressions like the address of a global yet. - // FIXME! - ConstantInt *CI = dyn_cast(C); - if (CI == 0) return 0; - APInt CVal = CI->getValue(); - // TODO: If CI is larger than 16-bytes, we can try slicing it in half to see - // if the top and bottom are the same. + // if the top and bottom are the same (e.g. for vectors and large integers). if (Size > 16) return 0; + + // If the constant is exactly 16 bytes, just use it. + if (Size == 16) return C; - // If this is a big endian target (PPC) then we need to bswap. - if (TD.isBigEndian()) - CVal = CVal.byteSwap(); - - // Determine what each byte of the pattern value should be. - char Value[16]; - for (unsigned i = 0; i != 16; ++i) { - // Get the byte value we're indexing into. - unsigned CByte = i % Size; - Value[i] = (unsigned char)(CVal.getZExtValue() >> CByte); - } - - return ConstantArray::get(V->getContext(), StringRef(Value, 16), false); + // Otherwise, we'll use an array of the constants. + unsigned ArraySize = 16/Size; + ArrayType *AT = ArrayType::get(V->getType(), ArraySize); + return ConstantArray::get(AT, std::vector(ArraySize, C)); } @@ -518,8 +499,7 @@ processLoopStridedStore(Value *DestPtr, unsigned StoreSize, PatternValue, ".memset_pattern"); GV->setUnnamedAddr(true); // Ok to merge these. GV->setAlignment(16); - Value *PatternPtr = Builder.CreateConstInBoundsGEP2_32(GV, 0, 0, "pattern"); - + Value *PatternPtr = ConstantExpr::getBitCast(GV, Builder.getInt8PtrTy()); NewCall = Builder.CreateCall3(MSP, BasePtr, PatternPtr, NumBytes); } diff --git a/test/Transforms/LoopIdiom/basic.ll b/test/Transforms/LoopIdiom/basic.ll index 122d25a22a0..485114c8d48 100644 --- a/test/Transforms/LoopIdiom/basic.ll +++ b/test/Transforms/LoopIdiom/basic.ll @@ -277,7 +277,7 @@ for.end13: ; preds = %for.inc10 ; On darwin10 (which is the triple in this .ll file) this loop can be turned ; into a memset_pattern call. ; rdar://9009151 -define void @test11(i32* nocapture %P) nounwind ssp { +define void @test11_pattern(i32* nocapture %P) nounwind ssp { entry: br label %for.body @@ -291,7 +291,7 @@ for.body: ; preds = %entry, %for.body for.end: ; preds = %for.body ret void -; CHECK: @test11 +; CHECK: @test11_pattern ; CHECK-NEXT: entry: ; CHECK-NEXT: bitcast ; CHECK-NEXT: memset_pattern @@ -322,3 +322,28 @@ for.end: ; preds = %for.body ; CHECK: ret void } +@G = global i32 5 + +; This store-of-address loop can be turned into a memset_pattern call. +; rdar://9009151 +define void @test13_pattern(i32** nocapture %P) nounwind ssp { +entry: + br label %for.body + +for.body: ; preds = %entry, %for.body + %indvar = phi i64 [ 0, %entry ], [ %indvar.next, %for.body ] + %arrayidx = getelementptr i32** %P, i64 %indvar + store i32* @G, i32** %arrayidx, align 4 + %indvar.next = add i64 %indvar, 1 + %exitcond = icmp eq i64 %indvar.next, 10000 + br i1 %exitcond, label %for.end, label %for.body + +for.end: ; preds = %for.body + ret void +; CHECK: @test13_pattern +; CHECK-NEXT: entry: +; CHECK-NEXT: bitcast +; CHECK-NEXT: memset_pattern +; CHECK-NOT: store +; CHECK: ret void +}