From 521efe68abac86ad0ed93284011a0ed5bb2b5f13 Mon Sep 17 00:00:00 2001 From: Dan Gohman Date: Tue, 16 Feb 2010 01:42:53 +0000 Subject: [PATCH] Split the main for-each-use loop again, this time for GenerateTruncates, as it also peeks at which registers are being used by other uses. This makes LSR less sensitive to use-list order. llvm-svn: 96308 --- .../Transforms/Scalar/LoopStrengthReduce.cpp | 5 +- llvm/test/CodeGen/X86/lsr-reuse-trunc.ll | 59 +++++++++++++++++++ 2 files changed, 63 insertions(+), 1 deletion(-) create mode 100644 llvm/test/CodeGen/X86/lsr-reuse-trunc.ll diff --git a/llvm/lib/Transforms/Scalar/LoopStrengthReduce.cpp b/llvm/lib/Transforms/Scalar/LoopStrengthReduce.cpp index 3e037815e75c..240b298b7268 100644 --- a/llvm/lib/Transforms/Scalar/LoopStrengthReduce.cpp +++ b/llvm/lib/Transforms/Scalar/LoopStrengthReduce.cpp @@ -2427,7 +2427,7 @@ void LSRInstance::GenerateCrossUseConstantOffsets() { /// GenerateAllReuseFormulae - Generate formulae for each use. void LSRInstance::GenerateAllReuseFormulae() { - // This is split into two loops so that hasRegsUsedByUsesOtherThan + // This is split into multiple loops so that hasRegsUsedByUsesOtherThan // queries are more precise. for (size_t LUIdx = 0, NumUses = Uses.size(); LUIdx != NumUses; ++LUIdx) { LSRUse &LU = Uses[LUIdx]; @@ -2446,6 +2446,9 @@ LSRInstance::GenerateAllReuseFormulae() { GenerateICmpZeroScales(LU, LUIdx, LU.Formulae[i]); for (size_t i = 0, f = LU.Formulae.size(); i != f; ++i) GenerateScales(LU, LUIdx, LU.Formulae[i]); + } + for (size_t LUIdx = 0, NumUses = Uses.size(); LUIdx != NumUses; ++LUIdx) { + LSRUse &LU = Uses[LUIdx]; for (size_t i = 0, f = LU.Formulae.size(); i != f; ++i) GenerateTruncates(LU, LUIdx, LU.Formulae[i]); } diff --git a/llvm/test/CodeGen/X86/lsr-reuse-trunc.ll b/llvm/test/CodeGen/X86/lsr-reuse-trunc.ll new file mode 100644 index 000000000000..d1d714491faa --- /dev/null +++ b/llvm/test/CodeGen/X86/lsr-reuse-trunc.ll @@ -0,0 +1,59 @@ +; RUN: llc < %s -march=x86-64 | FileCheck %s + +; Full strength reduction wouldn't reduce register pressure, so LSR should +; stick with indexing here. + +; CHECK: movaps (%rsi,%rax,4), %xmm3 +; CHECK: movaps %xmm3, (%rdi,%rax,4) +; CHECK: addq $4, %rax +; CHECK: cmpl %eax, (%rdx) +; CHECK-NEXT: jg + +define void @vvfloorf(float* nocapture %y, float* nocapture %x, i32* nocapture %n) nounwind { +entry: + %0 = load i32* %n, align 4 + %1 = icmp sgt i32 %0, 0 + br i1 %1, label %bb, label %return + +bb: + %indvar = phi i64 [ %indvar.next, %bb ], [ 0, %entry ] + %tmp = shl i64 %indvar, 2 + %scevgep = getelementptr float* %y, i64 %tmp + %scevgep9 = bitcast float* %scevgep to <4 x float>* + %scevgep10 = getelementptr float* %x, i64 %tmp + %scevgep1011 = bitcast float* %scevgep10 to <4 x float>* + %2 = load <4 x float>* %scevgep1011, align 16 + %3 = bitcast <4 x float> %2 to <4 x i32> + %4 = and <4 x i32> %3, + %5 = bitcast <4 x i32> %4 to <4 x float> + %6 = and <4 x i32> %3, + %7 = tail call <4 x float> @llvm.x86.sse.cmp.ps(<4 x float> %5, <4 x float> , i8 5) nounwind + %tmp.i4 = bitcast <4 x float> %7 to <4 x i32> + %8 = xor <4 x i32> %tmp.i4, + %9 = and <4 x i32> %8, + %10 = or <4 x i32> %9, %6 + %11 = bitcast <4 x i32> %10 to <4 x float> + %12 = fadd <4 x float> %2, %11 + %13 = fsub <4 x float> %12, %11 + %14 = tail call <4 x float> @llvm.x86.sse.cmp.ps(<4 x float> %2, <4 x float> %13, i8 1) nounwind + %15 = bitcast <4 x float> %14 to <4 x i32> + %16 = tail call <4 x float> @llvm.x86.sse2.cvtdq2ps(<4 x i32> %15) nounwind readnone + %17 = fadd <4 x float> %13, %16 + %tmp.i = bitcast <4 x float> %17 to <4 x i32> + %18 = or <4 x i32> %tmp.i, %6 + %19 = bitcast <4 x i32> %18 to <4 x float> + store <4 x float> %19, <4 x float>* %scevgep9, align 16 + %tmp12 = add i64 %tmp, 4 + %tmp13 = trunc i64 %tmp12 to i32 + %20 = load i32* %n, align 4 + %21 = icmp sgt i32 %20, %tmp13 + %indvar.next = add i64 %indvar, 1 + br i1 %21, label %bb, label %return + +return: + ret void +} + +declare <4 x float> @llvm.x86.sse.cmp.ps(<4 x float>, <4 x float>, i8) nounwind readnone + +declare <4 x float> @llvm.x86.sse2.cvtdq2ps(<4 x i32>) nounwind readnone