From e5f163a3b98a531c3ff35da0e97e7364c0e04b95 Mon Sep 17 00:00:00 2001 From: Nadav Rotem Date: Sun, 30 Sep 2012 06:24:14 +0000 Subject: A DAGCombine optimization for merging consecutive stores. This optimization is not profitable in many cases because moden processos can store multiple values in parallel, and preparing the consecutive store requires some work. We only handle these cases: 1. Consecutive stores where the values and consecutive loads. For example: int a = p->a; int b = p->b; q->a = a; q->b = b; 2. Consecutive stores where the values are constants. Foe example: q->a = 4; q->b = 5; git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@164910 91177308-0d34-0410-b5e6-96231b3b80d8 --- test/CodeGen/X86/MergeConsecutiveStores.ll | 150 +++++++++++++++++++++++++++++ 1 file changed, 150 insertions(+) create mode 100644 test/CodeGen/X86/MergeConsecutiveStores.ll (limited to 'test/CodeGen/X86/MergeConsecutiveStores.ll') diff --git a/test/CodeGen/X86/MergeConsecutiveStores.ll b/test/CodeGen/X86/MergeConsecutiveStores.ll new file mode 100644 index 0000000000..435f38c8ad --- /dev/null +++ b/test/CodeGen/X86/MergeConsecutiveStores.ll @@ -0,0 +1,150 @@ +; RUN: llc -march=x86-64 -mcpu=corei7 < %s | FileCheck %s + +target datalayout = "e-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f32:32:32-f64:64:64-v64:64:64-v128:128:128-a0:0:64-s0:64:64-f80:128:128-n8:16:32:64-S128" +target triple = "x86_64-apple-macosx10.8.0" + +%struct.A = type { i8, i8, i8, i8, i8, i8, i8, i8 } + +@a = common global [10000 x %struct.A] zeroinitializer, align 8 + +; Move all of the constants using a single vector store. +; CHECK: merge_const_store +; CHECK: movq %xmm0 +; CHECK: ret +define void @merge_const_store(i32 %count, %struct.A* nocapture %p) nounwind uwtable noinline ssp { + %1 = icmp sgt i32 %count, 0 + br i1 %1, label %.lr.ph, label %._crit_edge +.lr.ph: + %i.02 = phi i32 [ %10, %.lr.ph ], [ 0, %0 ] + %.01 = phi %struct.A* [ %11, %.lr.ph ], [ %p, %0 ] + %2 = getelementptr inbounds %struct.A* %.01, i64 0, i32 0 + store i8 1, i8* %2, align 1 + %3 = getelementptr inbounds %struct.A* %.01, i64 0, i32 1 + store i8 2, i8* %3, align 1 + %4 = getelementptr inbounds %struct.A* %.01, i64 0, i32 2 + store i8 3, i8* %4, align 1 + %5 = getelementptr inbounds %struct.A* %.01, i64 0, i32 3 + store i8 4, i8* %5, align 1 + %6 = getelementptr inbounds %struct.A* %.01, i64 0, i32 4 + store i8 5, i8* %6, align 1 + %7 = getelementptr inbounds %struct.A* %.01, i64 0, i32 5 + store i8 6, i8* %7, align 1 + %8 = getelementptr inbounds %struct.A* %.01, i64 0, i32 6 + store i8 7, i8* %8, align 1 + %9 = getelementptr inbounds %struct.A* %.01, i64 0, i32 7 + store i8 8, i8* %9, align 1 + %10 = add nsw i32 %i.02, 1 + %11 = getelementptr inbounds %struct.A* %.01, i64 1 + %exitcond = icmp eq i32 %10, %count + br i1 %exitcond, label %._crit_edge, label %.lr.ph +._crit_edge: + ret void +} + +; Move the first 4 constants as a single vector. Move the rest as scalars. +; CHECK: merge_nonconst_store +; CHECK: movd %xmm0 +; CHECK: movb +; CHECK: movb +; CHECK: movb +; CHECK: movb +; CHECK: ret +define void @merge_nonconst_store(i32 %count, i8 %zz, %struct.A* nocapture %p) nounwind uwtable noinline ssp { + %1 = icmp sgt i32 %count, 0 + br i1 %1, label %.lr.ph, label %._crit_edge +.lr.ph: + %i.02 = phi i32 [ %10, %.lr.ph ], [ 0, %0 ] + %.01 = phi %struct.A* [ %11, %.lr.ph ], [ %p, %0 ] + %2 = getelementptr inbounds %struct.A* %.01, i64 0, i32 0 + store i8 1, i8* %2, align 1 + %3 = getelementptr inbounds %struct.A* %.01, i64 0, i32 1 + store i8 2, i8* %3, align 1 + %4 = getelementptr inbounds %struct.A* %.01, i64 0, i32 2 + store i8 3, i8* %4, align 1 + %5 = getelementptr inbounds %struct.A* %.01, i64 0, i32 3 + store i8 4, i8* %5, align 1 + %6 = getelementptr inbounds %struct.A* %.01, i64 0, i32 4 + store i8 %zz, i8* %6, align 1 ; <----------- Not a const; + %7 = getelementptr inbounds %struct.A* %.01, i64 0, i32 5 + store i8 6, i8* %7, align 1 + %8 = getelementptr inbounds %struct.A* %.01, i64 0, i32 6 + store i8 7, i8* %8, align 1 + %9 = getelementptr inbounds %struct.A* %.01, i64 0, i32 7 + store i8 8, i8* %9, align 1 + %10 = add nsw i32 %i.02, 1 + %11 = getelementptr inbounds %struct.A* %.01, i64 1 + %exitcond = icmp eq i32 %10, %count + br i1 %exitcond, label %._crit_edge, label %.lr.ph +._crit_edge: + ret void +} + + +;CHECK: merge_loads +; load: +;CHECK: movw +; store: +;CHECK: movw +;CHECK: ret +define void @merge_loads(i32 %count, %struct.A* noalias nocapture %q, %struct.A* noalias nocapture %p) nounwind uwtable noinline ssp { + %1 = icmp sgt i32 %count, 0 + br i1 %1, label %.lr.ph, label %._crit_edge + +.lr.ph: ; preds = %0 + %2 = getelementptr inbounds %struct.A* %q, i64 0, i32 0 + %3 = getelementptr inbounds %struct.A* %q, i64 0, i32 1 + br label %4 + +;