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Hans Wennborg e8cda5736b Revert r314886 "[X86] Improvement in CodeGen instruction selection for LEAs (re-applying post required revision changes.)"
It broke the Chromium / SQLite build; see PR34830.

> Summary:
>    1/  Operand folding during complex pattern matching for LEAs has been
>        extended, such that it promotes Scale to accommodate similar operand
>        appearing in the DAG.
>        e.g.
>          T1 = A + B
>          T2 = T1 + 10
>          T3 = T2 + A
>        For above DAG rooted at T3, X86AddressMode will no look like
>          Base = B , Index = A , Scale = 2 , Disp = 10
>
>    2/  During OptimizeLEAPass down the pipeline factorization is now performed over LEAs
>        so that if there is an opportunity then complex LEAs (having 3 operands)
>        could be factored out.
>        e.g.
>          leal 1(%rax,%rcx,1), %rdx
>          leal 1(%rax,%rcx,2), %rcx
>        will be factored as following
>          leal 1(%rax,%rcx,1), %rdx
>          leal (%rdx,%rcx)   , %edx
>
>    3/ Aggressive operand folding for AM based selection for LEAs is sensitive to loops,
>       thus avoiding creation of any complex LEAs within a loop.
>
> Reviewers: lsaba, RKSimon, craig.topper, qcolombet, jmolloy
>
> Reviewed By: lsaba
>
> Subscribers: jmolloy, spatel, igorb, llvm-commits
>
>     Differential Revision: https://reviews.llvm.org/D35014

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@314919 91177308-0d34-0410-b5e6-96231b3b80d8
2017-10-04 17:54:06 +00:00

53 lines
2.0 KiB
LLVM

; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py
; RUN: llc < %s -mtriple=x86_64-unknown-linux-gnu | FileCheck %s
target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
target triple = "x86_64-unknown-linux-gnu"
@b = common local_unnamed_addr global i64 0, align 8
@a = common local_unnamed_addr global i8 0, align 1
; Function Attrs: norecurse nounwind uwtable
define void @c() local_unnamed_addr #0 {
; CHECK-LABEL: c:
; CHECK: # BB#0: # %entry
; CHECK-NEXT: movq {{.*}}(%rip), %rax
; CHECK-NEXT: leaq (%rax,%rax,4), %rcx
; CHECK-NEXT: negq %rcx
; CHECK-NEXT: leaq (%rax,%rax,8), %rax
; CHECK-NEXT: leaq (%rax,%rax,4), %rax
; CHECK-NEXT: testq %rax, %rcx
; CHECK-NEXT: je .LBB0_2
; CHECK-NEXT: # BB#1: # %if.then
; CHECK-NEXT: movb $0, {{.*}}(%rip)
; CHECK-NEXT: .LBB0_2: # %if.end
; CHECK-NEXT: retq
entry:
%0 = load i64, i64* @b, align 8, !tbaa !2
%mul = mul nsw i64 %0, -5
%mul1 = mul nsw i64 %0, 45
%and = and i64 %mul, %mul1
%tobool = icmp eq i64 %and, 0
br i1 %tobool, label %if.end, label %if.then
if.then: ; preds = %entry
store i8 0, i8* @a, align 1, !tbaa !6
br label %if.end
if.end: ; preds = %entry, %if.then
ret void
}
attributes #0 = { norecurse nounwind uwtable "correctly-rounded-divide-sqrt-fp-math"="false" "disable-tail-calls"="false" "less-precise-fpmad"="false" "no-frame-pointer-elim"="false" "no-infs-fp-math"="false" "no-jump-tables"="false" "no-nans-fp-math"="false" "no-signed-zeros-fp-math"="false" "no-trapping-math"="false" "stack-protector-buffer-size"="8" "target-cpu"="x86-64" "target-features"="+fxsr,+mmx,+sse,+sse2,+x87" "unsafe-fp-math"="false" "use-soft-float"="false" }
!llvm.module.flags = !{!0}
!llvm.ident = !{!1}
!0 = !{i32 1, !"wchar_size", i32 4}
!1 = !{!"clang version 6.0.0 "}
!2 = !{!3, !3, i64 0}
!3 = !{!"long", !4, i64 0}
!4 = !{!"omnipotent char", !5, i64 0}
!5 = !{!"Simple C/C++ TBAA"}
!6 = !{!4, !4, i64 0}