mirror of
https://github.com/RPCS3/llvm-mirror.git
synced 2024-10-20 03:23:01 +02:00
161d927dda
During the SeparateConstOffsetFromGEP pass, signed extensions are distributed to the values that feed into them and then later recombined. The recombination stage is somewhat problematic- it doesn't differ add and sub instructions from another when matching the sext(a) +/- sext(b) -> sext(a +/- b) pattern in some instances. An example- the IR contains: %unextendedA %unextendedB %subuAuB = unextendedA - unextendedB %extA = extend A %extB = extend B %addeAeB = extA + extB The problematic optimization will transform that into: %unextendedA %unextendedB %subuAuB = unextendedA - unextendedB %extA = extend A %extB = extend B %addeAeB = extend subuAuB ; Obviously not semantically equivalent to the IR input. This patch fixes that. Patch by Drew Wock <drew.wock@sas.com> Differential Revision: https://reviews.llvm.org/D65967
32 lines
1.2 KiB
LLVM
32 lines
1.2 KiB
LLVM
; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
|
|
; RUN: opt -S -separate-const-offset-from-gep < %s | FileCheck %s
|
|
|
|
define void @matchingExtensions(i32* %ap, i32* %bp, i64* %result) {
|
|
; CHECK-LABEL: @matchingExtensions(
|
|
; CHECK-NEXT: entry:
|
|
; CHECK-NEXT: [[A:%.*]] = load i32, i32* [[AP:%.*]]
|
|
; CHECK-NEXT: [[B:%.*]] = load i32, i32* [[BP:%.*]]
|
|
; CHECK-NEXT: [[EB:%.*]] = sext i32 [[B]] to i64
|
|
; CHECK-NEXT: [[SUBAB:%.*]] = sub nsw i32 [[A]], [[B]]
|
|
; CHECK-NEXT: [[EA:%.*]] = sext i32 [[A]] to i64
|
|
; CHECK-NEXT: [[ADDEAEB:%.*]] = add nsw i64 [[EA]], [[EB]]
|
|
; CHECK-NEXT: [[EXTSUB:%.*]] = sext i32 [[SUBAB]] to i64
|
|
; CHECK-NEXT: [[IDX:%.*]] = getelementptr i32, i32* [[AP]], i64 [[EXTSUB]]
|
|
; CHECK-NEXT: store i64 [[ADDEAEB]], i64* [[RESULT:%.*]]
|
|
; CHECK-NEXT: store i32 [[SUBAB]], i32* [[IDX]]
|
|
; CHECK-NEXT: ret void
|
|
;
|
|
entry:
|
|
%a = load i32, i32* %ap
|
|
%b = load i32, i32* %bp
|
|
%eb = sext i32 %b to i64
|
|
%subab = sub nsw i32 %a, %b
|
|
%ea = sext i32 %a to i64
|
|
%addeaeb = add nsw i64 %ea, %eb
|
|
%extsub = sext i32 %subab to i64
|
|
%idx = getelementptr i32, i32* %ap, i64 %extsub
|
|
store i64 %addeaeb, i64* %result
|
|
store i32 %subab, i32* %idx
|
|
ret void
|
|
}
|