llvm-6502/test/CodeGen/X86/merge_store.ll
Juergen Ributzka 915e936de2 Teach BaseIndexOffset::match to identify base pointers in loops.
The small utility function that pattern matches Base + Index +
Offset patterns for loads and stores fails to recognize the base
pointer for loads/stores from/into an array at offset 0 inside a
loop. As a result DAGCombiner::MergeConsecutiveStores was not able
to merge all stores.

This commit fixes the issue by adding an additional pattern match
and also a test case.

Reviewer: Nadav

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@188936 91177308-0d34-0410-b5e6-96231b3b80d8
2013-08-21 21:53:38 +00:00

31 lines
956 B
LLVM

; RUN: llc < %s -mtriple=x86_64-unknown-unknown -mcpu=x86-64 | FileCheck %s
define void @merge_store(i32* nocapture %a) {
; CHECK-LABEL: merge_store:
; CHECK: movq
; CHECK: movq
entry:
br label %for.body
for.body:
%indvars.iv = phi i64 [ 0, %entry ], [ %indvars.iv.next, %for.body ]
%arrayidx = getelementptr inbounds i32* %a, i64 %indvars.iv
store i32 1, i32* %arrayidx, align 4
%0 = or i64 %indvars.iv, 1
%arrayidx2 = getelementptr inbounds i32* %a, i64 %0
store i32 1, i32* %arrayidx2, align 4
%1 = or i64 %indvars.iv, 2
%arrayidx5 = getelementptr inbounds i32* %a, i64 %1
store i32 1, i32* %arrayidx5, align 4
%2 = or i64 %indvars.iv, 3
%arrayidx8 = getelementptr inbounds i32* %a, i64 %2
store i32 1, i32* %arrayidx8, align 4
%indvars.iv.next = add nuw nsw i64 %indvars.iv, 4
%3 = trunc i64 %indvars.iv.next to i32
%cmp = icmp slt i32 %3, 1000
br i1 %cmp, label %for.body, label %for.end
for.end:
ret void
}