llvm-6502/test/Transforms/StraightLineStrengthReduce/X86/no-slsr.ll
Jingyue Wu 423476d899 [SLSR] garbage-collect unused instructions
Summary:
After we rewrite a candidate, the instructions used by the old form may
become unused. This patch cleans up these unused instructions so that we
needn't run DCE after SLSR.

Test Plan: removed -dce in all the SLSR tests

Reviewers: broune, meheff

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D9101

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@235410 91177308-0d34-0410-b5e6-96231b3b80d8
2015-04-21 19:56:18 +00:00

45 lines
1.2 KiB
LLVM

; RUN: opt < %s -slsr -gvn -S | FileCheck %s
target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
target triple = "x86_64-unknown-linux-gnu"
; Do not perform SLSR on &input[s] and &input[s * 2] which fit into addressing
; modes of X86.
define i32 @no_slsr_gep(i32* %input, i64 %s) {
; CHECK-LABEL: @no_slsr_gep(
; v0 = input[0];
%p0 = getelementptr inbounds i32, i32* %input, i64 0
%v0 = load i32, i32* %p0
; v1 = input[s];
%p1 = getelementptr inbounds i32, i32* %input, i64 %s
; CHECK: %p1 = getelementptr inbounds i32, i32* %input, i64 %s
%v1 = load i32, i32* %p1
; v2 = input[s * 2];
%s2 = mul nsw i64 %s, 2
%p2 = getelementptr inbounds i32, i32* %input, i64 %s2
; CHECK: %p2 = getelementptr inbounds i32, i32* %input, i64 %s2
%v2 = load i32, i32* %p2
; return v0 + v1 + v2;
%1 = add i32 %v0, %v1
%2 = add i32 %1, %v2
ret i32 %2
}
define void @no_slsr_add(i32 %b, i32 %s) {
; CHECK-LABEL: @no_slsr_add(
%1 = add i32 %b, %s
; CHECK: add i32 %b, %s
call void @foo(i32 %1)
%s2 = mul i32 %s, 2
; CHECK: %s2 = mul i32 %s, 2
%2 = add i32 %b, %s2
; CHECK: add i32 %b, %s2
call void @foo(i32 %2)
ret void
}
declare void @foo(i32 %a)