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mirror of https://github.com/RPCS3/llvm-mirror.git synced 2025-01-31 20:51:52 +01:00
Sam Parker e4a5828aa1 [ARM][ParallelDSP] Change search for muls
rL369567 reverted a couple of recent changes made to ARMParallelDSP
because of a miscompilation error: PR43073.

The issue stemmed from an underlying bug that was caused by adding
muls into a reduction before it was proved that they could be executed
in parallel with another mul.

Most of the changes here are from the previously reverted commits.
The additional changes have been made area:
1) The Search function now doesn't insert any muls into the Reduction
   object. That now happens once the search has successfully finished.
2) For any muls added into the reduction but that weren't paired, we
   accumulate their values as an input into the smlad.

Differential Revision: https://reviews.llvm.org/D66660

llvm-svn: 370171
2019-08-28 08:51:13 +00:00

85 lines
3.6 KiB
LLVM

; RUN: opt -mtriple=thumbv7-unknown-linux-android -arm-parallel-dsp -S %s -o - | FileCheck %s
; CHECK-LABEL: undef_no_return
; CHECK: [[CAST_A:%[^ ]+]] = bitcast i16* %incdec.ptr21 to i32*
; CHECK: [[LOAD_A:%[^ ]+]] = load i32, i32* [[CAST_A]], align 2
; CHECK: %uglygep15 = getelementptr i8, i8* undef, i32 undef
; CHECK: [[GEP8:%[^ ]+]] = getelementptr i8, i8* undef, i32 undef
; CHECK: [[CAST_GEP8:%[^ ]+]] = bitcast i8* [[GEP8]] to i16*
; CHECK: [[GEP16:%[^ ]+]] = getelementptr i16, i16* [[CAST_GEP8]], i32 6
; CHECK: [[CAST_GEP16:%[^ ]+]] = bitcast i16* [[GEP16]] to i32*
; CHECK: [[LOAD_UNDEF:%[^ ]+]] = load i32, i32* [[CAST_GEP16]], align 2
; CHECK: call i32 @llvm.arm.smladx(i32 [[LOAD_UNDEF]], i32 [[LOAD_A]], i32 undef)
define void @undef_no_return(i16* %a) {
entry:
%incdec.ptr21 = getelementptr inbounds i16, i16* %a, i32 3
%incdec.ptr29 = getelementptr inbounds i16, i16* %a, i32 4
br label %for.body
for.body:
%0 = load i16, i16* %incdec.ptr21, align 2
%conv25 = sext i16 %0 to i32
%uglygep15 = getelementptr i8, i8* undef, i32 undef
%uglygep1516 = bitcast i8* %uglygep15 to i16*
%scevgep17 = getelementptr i16, i16* %uglygep1516, i32 7
%1 = load i16, i16* %scevgep17, align 2
%conv31 = sext i16 %1 to i32
%2 = load i16, i16* %incdec.ptr29, align 2
%conv33 = sext i16 %2 to i32
%uglygep12 = getelementptr i8, i8* undef, i32 undef
%uglygep1213 = bitcast i8* %uglygep12 to i16*
%scevgep14 = getelementptr i16, i16* %uglygep1213, i32 6
%3 = load i16, i16* %scevgep14, align 2
%conv39 = sext i16 %3 to i32
%mul.i287.neg.neg = mul nsw i32 %conv31, %conv25
%mul.i283.neg.neg = mul nsw i32 %conv39, %conv33
%reass.add408 = add i32 undef, %mul.i287.neg.neg
%reass.add409 = add i32 %reass.add408, %mul.i283.neg.neg
br label %for.body
}
; CHECK-LABEL: return
; CHECK: phi i32 [ %N, %entry ]
; CHECK: [[ACC:%[^ ]+]] = phi i32 [ 0, %entry ], [ [[ACC_NEXT:%[^ ]+]], %for.body ]
; CHECK: [[CAST_A:%[^ ]+]] = bitcast i16* %incdec.ptr21 to i32*
; CHECK: [[LOAD_A:%[^ ]+]] = load i32, i32* [[CAST_A]], align 2
; CHECK: [[GEP8:%[^ ]+]] = getelementptr i8, i8* %b, i32 0
; CHECK: [[CAST_GEP8:%[^ ]+]] = bitcast i8* [[GEP8]] to i16*
; CHECK: [[GEP16:%[^ ]+]] = getelementptr i16, i16* [[CAST_GEP8]], i32 %iv
; CHECK: [[CAST_GEP16:%[^ ]+]] = bitcast i16* [[GEP16]] to i32*
; CHECK: [[LOAD_B:%[^ ]+]] = load i32, i32* [[CAST_GEP16]], align 2
; CHECK: [[ACC_NEXT]] = call i32 @llvm.arm.smladx(i32 [[LOAD_B]], i32 [[LOAD_A]], i32 [[ACC]])
define i32 @return(i16* %a, i8* %b, i32 %N) {
entry:
%incdec.ptr21 = getelementptr inbounds i16, i16* %a, i32 3
%incdec.ptr29 = getelementptr inbounds i16, i16* %a, i32 4
br label %for.body
for.body:
%iv = phi i32 [ %N, %entry ], [ %iv.next, %for.body ]
%acc = phi i32 [ 0, %entry ], [ %reass.add409, %for.body ]
%0 = load i16, i16* %incdec.ptr21, align 2
%conv25 = sext i16 %0 to i32
%uglygep15 = getelementptr i8, i8* %b, i32 0
%uglygep1516 = bitcast i8* %uglygep15 to i16*
%b.idx = add nuw nsw i32 %iv, 1
%scevgep17 = getelementptr i16, i16* %uglygep1516, i32 %b.idx
%scevgep14 = getelementptr i16, i16* %uglygep1516, i32 %iv
%1 = load i16, i16* %scevgep17, align 2
%conv31 = sext i16 %1 to i32
%2 = load i16, i16* %incdec.ptr29, align 2
%conv33 = sext i16 %2 to i32
%3 = load i16, i16* %scevgep14, align 2
%conv39 = sext i16 %3 to i32
%mul.i287.neg.neg = mul nsw i32 %conv31, %conv25
%mul.i283.neg.neg = mul nsw i32 %conv39, %conv33
%reass.add408 = add i32 %acc, %mul.i287.neg.neg
%reass.add409 = add i32 %reass.add408, %mul.i283.neg.neg
%iv.next = add nuw nsw i32 %iv, -1
%cmp = icmp ne i32 %iv.next, 0
br i1 %cmp, label %for.body, label %exit
exit:
ret i32 %reass.add409
}