[Better late than never!] Hi Sanjay,
Your patch seems to have fixed the regression. Thanks! On Wed, 14 Jul 2021 at 19:14, Sanjay Patel <spa...@rotateright.com> wrote: > I have a hunch about what went wrong. Please see if this commit changes > anything for you: > https://reviews.llvm.org/rGca6e117d8634 > > On Wed, Jul 14, 2021 at 11:12 AM Sanjay Patel <spa...@rotateright.com> > wrote: > >> Thanks for letting me know. I could use some help to repro because I'm >> not very familiar with that benchmark or ARM32. >> 1. Can you provide the unoptimized IR for "BZ2_decompress"? >> 2. What is the particular flavor/CPU of ARM32 to target? >> 3. Was there a speed regression in addition to the size regression? >> >> If you can file a bugzilla with any of this, that would be best of >> course. That way, we can pull in ARM or other experts as needed if this is >> a codegen issue or problem with another IR pass. >> >> >> On Wed, Jul 14, 2021 at 10:55 AM Maxim Kuvyrkov < >> maxim.kuvyr...@linaro.org> wrote: >> >>> Hi Sanjay, >>> >>> On 32-bit ARM your patch appears to increase code size of BZ2_decompress >>> from SPEC2006’s 401.bzip2 by 50% — from 7.5K to 11K. This increases >>> overall code size of 401.bzip2 benchmark by 10%. >>> >>> Would you please investigate? >>> >>> Please let us know if you need help reproducing the problem. >>> >>> Regards, >>> >>> -- >>> Maxim Kuvyrkov >>> https://www.linaro.org >>> >>> > On 14 Jul 2021, at 17:32, ci_not...@linaro.org wrote: >>> > >>> > Successfully identified regression in *llvm* in CI configuration >>> tcwg_bmk_llvm_tk1/llvm-master-arm-spec2k6-Os. So far, this commit has >>> regressed CI configurations: >>> > - tcwg_bmk_llvm_tk1/llvm-master-arm-spec2k6-Os >>> > >>> > Culprit: >>> > <cut> >>> > commit 40b752d28d95158e52dba7cfeea92e41b7ccff9a >>> > Author: Sanjay Patel <spa...@rotateright.com> >>> > Date: Mon Jul 5 09:57:39 2021 -0400 >>> > >>> > [InstCombine] fold icmp slt/sgt of offset value with constant >>> > >>> > This follows up patches for the unsigned siblings: >>> > 0c400e895306 >>> > c7b658aeb526 >>> > >>> > We are translating an offset signed compare to its >>> > unsigned equivalent when one end of the range is >>> > at the limit (zero or unsigned max). >>> > >>> > (X + C2) >s C --> X <u (SMAX - C) (if C == C2 - 1) >>> > (X + C2) <s C --> X >u (C ^ SMAX) (if C == C2) >>> > >>> > This probably does not show up much in IR derived >>> > from C/C++ source because that would likely have >>> > 'nsw', and we have folds for that already. >>> > >>> > As with the previous unsigned transforms, the folds >>> > could be generalized to handle non-constant patterns: >>> > >>> > https://alive2.llvm.org/ce/z/Y8Xrrm >>> > >>> > ; sgt >>> > define i1 @src(i8 %a, i8 %c) { >>> > %c2 = add i8 %c, 1 >>> > %t = add i8 %a, %c2 >>> > %ov = icmp sgt i8 %t, %c >>> > ret i1 %ov >>> > } >>> > >>> > define i1 @tgt(i8 %a, i8 %c) { >>> > %c_off = sub i8 127, %c ; SMAX >>> > %ov = icmp ult i8 %a, %c_off >>> > ret i1 %ov >>> > } >>> > >>> > https://alive2.llvm.org/ce/z/c8uhnk >>> > >>> > ; slt >>> > define i1 @src(i8 %a, i8 %c) { >>> > %t = add i8 %a, %c >>> > %ov = icmp slt i8 %t, %c >>> > ret i1 %ov >>> > } >>> > >>> > define i1 @tgt(i8 %a, i8 %c) { >>> > %c_offnot = xor i8 %c, 127 ; SMAX >>> > %ov = icmp ugt i8 %a, %c_offnot >>> > ret i1 %ov >>> > } >>> > </cut> >>> > >>> > Results regressed to (for first_bad == >>> 40b752d28d95158e52dba7cfeea92e41b7ccff9a) >>> > # reset_artifacts: >>> > -10 >>> > # build_abe binutils: >>> > -9 >>> > # build_abe stage1 -- --set gcc_override_configure=--with-mode=thumb >>> --set gcc_override_configure=--disable-libsanitizer: >>> > -8 >>> > # build_abe linux: >>> > -7 >>> > # build_abe glibc: >>> > -6 >>> > # build_abe stage2 -- --set gcc_override_configure=--with-mode=thumb >>> --set gcc_override_configure=--disable-libsanitizer: >>> > -5 >>> > # build_llvm true: >>> > -3 >>> > # true: >>> > 0 >>> > # benchmark -Os_mthumb -- >>> artifacts/build-40b752d28d95158e52dba7cfeea92e41b7ccff9a/results_id: >>> > 1 >>> > # 401.bzip2,bzip2_base.default >>> regressed by 110 >>> > # 401.bzip2,[.] BZ2_decompress >>> regressed by 149 >>> > >>> > from (for last_good == 32dd914f7182875730eb3453f39dcc584b7219b2) >>> > # reset_artifacts: >>> > -10 >>> > # build_abe binutils: >>> > -9 >>> > # build_abe stage1 -- --set gcc_override_configure=--with-mode=thumb >>> --set gcc_override_configure=--disable-libsanitizer: >>> > -8 >>> > # build_abe linux: >>> > -7 >>> > # build_abe glibc: >>> > -6 >>> > # build_abe stage2 -- --set gcc_override_configure=--with-mode=thumb >>> --set gcc_override_configure=--disable-libsanitizer: >>> > -5 >>> > # build_llvm true: >>> > -3 >>> > # true: >>> > 0 >>> > # benchmark -Os_mthumb -- >>> artifacts/build-32dd914f7182875730eb3453f39dcc584b7219b2/results_id: >>> > 1 >>> > >>> > Artifacts of last_good build: >>> https://ci.linaro.org/job/tcwg_bmk_ci_llvm-bisect-tcwg_bmk_tk1-llvm-master-arm-spec2k6-Os/9/artifact/artifacts/build-32dd914f7182875730eb3453f39dcc584b7219b2/ >>> > Results ID of last_good: >>> tk1_32/tcwg_bmk_llvm_tk1/bisect-llvm-master-arm-spec2k6-Os/1631 >>> > Artifacts of first_bad build: >>> https://ci.linaro.org/job/tcwg_bmk_ci_llvm-bisect-tcwg_bmk_tk1-llvm-master-arm-spec2k6-Os/9/artifact/artifacts/build-40b752d28d95158e52dba7cfeea92e41b7ccff9a/ >>> > Results ID of first_bad: >>> tk1_32/tcwg_bmk_llvm_tk1/bisect-llvm-master-arm-spec2k6-Os/1622 >>> > Build top page/logs: >>> https://ci.linaro.org/job/tcwg_bmk_ci_llvm-bisect-tcwg_bmk_tk1-llvm-master-arm-spec2k6-Os/9/ >>> > >>> > Configuration details: >>> > >>> > >>> > Reproduce builds: >>> > <cut> >>> > mkdir investigate-llvm-40b752d28d95158e52dba7cfeea92e41b7ccff9a >>> > cd investigate-llvm-40b752d28d95158e52dba7cfeea92e41b7ccff9a >>> > >>> > git clone https://git.linaro.org/toolchain/jenkins-scripts >>> > >>> > mkdir -p artifacts/manifests >>> > curl -o artifacts/manifests/build-baseline.sh >>> https://ci.linaro.org/job/tcwg_bmk_ci_llvm-bisect-tcwg_bmk_tk1-llvm-master-arm-spec2k6-Os/9/artifact/artifacts/manifests/build-baseline.sh >>> --fail >>> > curl -o artifacts/manifests/build-parameters.sh >>> https://ci.linaro.org/job/tcwg_bmk_ci_llvm-bisect-tcwg_bmk_tk1-llvm-master-arm-spec2k6-Os/9/artifact/artifacts/manifests/build-parameters.sh >>> --fail >>> > curl -o artifacts/test.sh >>> https://ci.linaro.org/job/tcwg_bmk_ci_llvm-bisect-tcwg_bmk_tk1-llvm-master-arm-spec2k6-Os/9/artifact/artifacts/test.sh >>> --fail >>> > chmod +x artifacts/test.sh >>> > >>> > # Reproduce the baseline build (build all pre-requisites) >>> > ./jenkins-scripts/tcwg_bmk-build.sh @@ >>> artifacts/manifests/build-baseline.sh >>> > >>> > # Save baseline build state (which is then restored in >>> artifacts/test.sh) >>> > rsync -a --del --delete-excluded --exclude bisect/ --exclude >>> artifacts/ --exclude llvm/ ./ ./bisect/baseline/ >>> > >>> > cd llvm >>> > >>> > # Reproduce first_bad build >>> > git checkout --detach 40b752d28d95158e52dba7cfeea92e41b7ccff9a >>> > ../artifacts/test.sh >>> > >>> > # Reproduce last_good build >>> > git checkout --detach 32dd914f7182875730eb3453f39dcc584b7219b2 >>> > ../artifacts/test.sh >>> > >>> > cd .. >>> > </cut> >>> > >>> > History of pending regressions and results: >>> https://git.linaro.org/toolchain/ci/base-artifacts.git/log/?h=linaro-local/ci/tcwg_bmk_llvm_tk1/llvm-master-arm-spec2k6-Os >>> > >>> > Artifacts: >>> https://ci.linaro.org/job/tcwg_bmk_ci_llvm-bisect-tcwg_bmk_tk1-llvm-master-arm-spec2k6-Os/9/artifact/artifacts/ >>> > Build log: >>> https://ci.linaro.org/job/tcwg_bmk_ci_llvm-bisect-tcwg_bmk_tk1-llvm-master-arm-spec2k6-Os/9/consoleText >>> > >>> > Full commit (up to 1000 lines): >>> > <cut> >>> > commit 40b752d28d95158e52dba7cfeea92e41b7ccff9a >>> > Author: Sanjay Patel <spa...@rotateright.com> >>> > Date: Mon Jul 5 09:57:39 2021 -0400 >>> > >>> > [InstCombine] fold icmp slt/sgt of offset value with constant >>> > >>> > This follows up patches for the unsigned siblings: >>> > 0c400e895306 >>> > c7b658aeb526 >>> > >>> > We are translating an offset signed compare to its >>> > unsigned equivalent when one end of the range is >>> > at the limit (zero or unsigned max). >>> > >>> > (X + C2) >s C --> X <u (SMAX - C) (if C == C2 - 1) >>> > (X + C2) <s C --> X >u (C ^ SMAX) (if C == C2) >>> > >>> > This probably does not show up much in IR derived >>> > from C/C++ source because that would likely have >>> > 'nsw', and we have folds for that already. >>> > >>> > As with the previous unsigned transforms, the folds >>> > could be generalized to handle non-constant patterns: >>> > >>> > https://alive2.llvm.org/ce/z/Y8Xrrm >>> > >>> > ; sgt >>> > define i1 @src(i8 %a, i8 %c) { >>> > %c2 = add i8 %c, 1 >>> > %t = add i8 %a, %c2 >>> > %ov = icmp sgt i8 %t, %c >>> > ret i1 %ov >>> > } >>> > >>> > define i1 @tgt(i8 %a, i8 %c) { >>> > %c_off = sub i8 127, %c ; SMAX >>> > %ov = icmp ult i8 %a, %c_off >>> > ret i1 %ov >>> > } >>> > >>> > https://alive2.llvm.org/ce/z/c8uhnk >>> > >>> > ; slt >>> > define i1 @src(i8 %a, i8 %c) { >>> > %t = add i8 %a, %c >>> > %ov = icmp slt i8 %t, %c >>> > ret i1 %ov >>> > } >>> > >>> > define i1 @tgt(i8 %a, i8 %c) { >>> > %c_offnot = xor i8 %c, 127 ; SMAX >>> > %ov = icmp ugt i8 %a, %c_offnot >>> > ret i1 %ov >>> > } >>> > --- >>> > .../Transforms/InstCombine/InstCombineCompares.cpp | 21 >>> ++++++++++++++------- >>> > llvm/test/Transforms/InstCombine/icmp-add.ll | 20 >>> ++++++++++---------- >>> > 2 files changed, 24 insertions(+), 17 deletions(-) >>> > >>> > diff --git a/llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp >>> b/llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp >>> > index 6bd479def210..6e66c61f5e46 100644 >>> > --- a/llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp >>> > +++ b/llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp >>> > @@ -2636,20 +2636,27 @@ Instruction >>> *InstCombinerImpl::foldICmpAddConstant(ICmpInst &Cmp, >>> > // Fold icmp pred (add X, C2), C. >>> > Value *X = Add->getOperand(0); >>> > Type *Ty = Add->getType(); >>> > - CmpInst::Predicate Pred = Cmp.getPredicate(); >>> > + const CmpInst::Predicate Pred = Cmp.getPredicate(); >>> > + const APInt SMax = >>> APInt::getSignedMaxValue(Ty->getScalarSizeInBits()); >>> > + const APInt SMin = >>> APInt::getSignedMinValue(Ty->getScalarSizeInBits()); >>> > >>> > - // Fold an unsigned compare with offset to signed compare: >>> > + // Fold compare with offset to opposite sign compare if it >>> eliminates offset: >>> > // (X + C2) >u C --> X <s -C2 (if C == C2 + SMAX) >>> > - // TODO: Find the signed predicate siblings. >>> > - if (Pred == CmpInst::ICMP_UGT && >>> > - C == *C2 + APInt::getSignedMaxValue(Ty->getScalarSizeInBits())) >>> > + if (Pred == CmpInst::ICMP_UGT && C == *C2 + SMax) >>> > return new ICmpInst(ICmpInst::ICMP_SLT, X, ConstantInt::get(Ty, >>> -(*C2))); >>> > >>> > // (X + C2) <u C --> X >s ~C2 (if C == C2 + SMIN) >>> > - if (Pred == CmpInst::ICMP_ULT && >>> > - C == *C2 + APInt::getSignedMinValue(Ty->getScalarSizeInBits())) >>> > + if (Pred == CmpInst::ICMP_ULT && C == *C2 + SMin) >>> > return new ICmpInst(ICmpInst::ICMP_SGT, X, ConstantInt::get(Ty, >>> ~(*C2))); >>> > >>> > + // (X + C2) >s C --> X <u (SMAX - C) (if C == C2 - 1) >>> > + if (Pred == CmpInst::ICMP_SGT && C == *C2 - 1) >>> > + return new ICmpInst(ICmpInst::ICMP_ULT, X, ConstantInt::get(Ty, >>> SMax - C)); >>> > + >>> > + // (X + C2) <s C --> X >u (C ^ SMAX) (if C == C2) >>> > + if (Pred == CmpInst::ICMP_SLT && C == *C2) >>> > + return new ICmpInst(ICmpInst::ICMP_UGT, X, ConstantInt::get(Ty, C >>> ^ SMax)); >>> > + >>> > // If the add does not wrap, we can always adjust the compare by >>> subtracting >>> > // the constants. Equality comparisons are handled elsewhere. >>> SGE/SLE/UGE/ULE >>> > // are canonicalized to SGT/SLT/UGT/ULT. >>> > diff --git a/llvm/test/Transforms/InstCombine/icmp-add.ll >>> b/llvm/test/Transforms/InstCombine/icmp-add.ll >>> > index 1f00dc6e2992..aa69325d716c 100644 >>> > --- a/llvm/test/Transforms/InstCombine/icmp-add.ll >>> > +++ b/llvm/test/Transforms/InstCombine/icmp-add.ll >>> > @@ -842,8 +842,7 @@ define i1 @ult_wrong_offset(i8 %a) { >>> > >>> > define i1 @sgt_offset(i8 %a) { >>> > ; CHECK-LABEL: @sgt_offset( >>> > -; CHECK-NEXT: [[T:%.*]] = add i8 [[A:%.*]], -6 >>> > -; CHECK-NEXT: [[OV:%.*]] = icmp sgt i8 [[T]], -7 >>> > +; CHECK-NEXT: [[OV:%.*]] = icmp ult i8 [[A:%.*]], -122 >>> > ; CHECK-NEXT: ret i1 [[OV]] >>> > ; >>> > %t = add i8 %a, -6 >>> > @@ -855,7 +854,7 @@ define i1 @sgt_offset_use(i32 %a) { >>> > ; CHECK-LABEL: @sgt_offset_use( >>> > ; CHECK-NEXT: [[T:%.*]] = add i32 [[A:%.*]], 42 >>> > ; CHECK-NEXT: call void @use(i32 [[T]]) >>> > -; CHECK-NEXT: [[OV:%.*]] = icmp sgt i32 [[T]], 41 >>> > +; CHECK-NEXT: [[OV:%.*]] = icmp ult i32 [[A]], 2147483606 >>> > ; CHECK-NEXT: ret i1 [[OV]] >>> > ; >>> > %t = add i32 %a, 42 >>> > @@ -866,8 +865,7 @@ define i1 @sgt_offset_use(i32 %a) { >>> > >>> > define <2 x i1> @sgt_offset_splat(<2 x i5> %a) { >>> > ; CHECK-LABEL: @sgt_offset_splat( >>> > -; CHECK-NEXT: [[T:%.*]] = add <2 x i5> [[A:%.*]], <i5 9, i5 9> >>> > -; CHECK-NEXT: [[OV:%.*]] = icmp sgt <2 x i5> [[T]], <i5 8, i5 8> >>> > +; CHECK-NEXT: [[OV:%.*]] = icmp ult <2 x i5> [[A:%.*]], <i5 7, i5 >>> 7> >>> > ; CHECK-NEXT: ret <2 x i1> [[OV]] >>> > ; >>> > %t = add <2 x i5> %a, <i5 9, i5 9> >>> > @@ -875,6 +873,8 @@ define <2 x i1> @sgt_offset_splat(<2 x i5> %a) { >>> > ret <2 x i1> %ov >>> > } >>> > >>> > +; negative test - constants must differ by 1 >>> > + >>> > define i1 @sgt_wrong_offset(i8 %a) { >>> > ; CHECK-LABEL: @sgt_wrong_offset( >>> > ; CHECK-NEXT: [[T:%.*]] = add i8 [[A:%.*]], -7 >>> > @@ -888,8 +888,7 @@ define i1 @sgt_wrong_offset(i8 %a) { >>> > >>> > define i1 @slt_offset(i8 %a) { >>> > ; CHECK-LABEL: @slt_offset( >>> > -; CHECK-NEXT: [[T:%.*]] = add i8 [[A:%.*]], -6 >>> > -; CHECK-NEXT: [[OV:%.*]] = icmp slt i8 [[T]], -6 >>> > +; CHECK-NEXT: [[OV:%.*]] = icmp ugt i8 [[A:%.*]], -123 >>> > ; CHECK-NEXT: ret i1 [[OV]] >>> > ; >>> > %t = add i8 %a, -6 >>> > @@ -901,7 +900,7 @@ define i1 @slt_offset_use(i32 %a) { >>> > ; CHECK-LABEL: @slt_offset_use( >>> > ; CHECK-NEXT: [[T:%.*]] = add i32 [[A:%.*]], 42 >>> > ; CHECK-NEXT: call void @use(i32 [[T]]) >>> > -; CHECK-NEXT: [[OV:%.*]] = icmp slt i32 [[T]], 42 >>> > +; CHECK-NEXT: [[OV:%.*]] = icmp ugt i32 [[A]], 2147483605 >>> > ; CHECK-NEXT: ret i1 [[OV]] >>> > ; >>> > %t = add i32 %a, 42 >>> > @@ -912,8 +911,7 @@ define i1 @slt_offset_use(i32 %a) { >>> > >>> > define <2 x i1> @slt_offset_splat(<2 x i5> %a) { >>> > ; CHECK-LABEL: @slt_offset_splat( >>> > -; CHECK-NEXT: [[T:%.*]] = add <2 x i5> [[A:%.*]], <i5 9, i5 9> >>> > -; CHECK-NEXT: [[OV:%.*]] = icmp slt <2 x i5> [[T]], <i5 9, i5 9> >>> > +; CHECK-NEXT: [[OV:%.*]] = icmp ugt <2 x i5> [[A:%.*]], <i5 6, i5 >>> 6> >>> > ; CHECK-NEXT: ret <2 x i1> [[OV]] >>> > ; >>> > %t = add <2 x i5> %a, <i5 9, i5 9> >>> > @@ -921,6 +919,8 @@ define <2 x i1> @slt_offset_splat(<2 x i5> %a) { >>> > ret <2 x i1> %ov >>> > } >>> > >>> > +; negative test - constants must be equal >>> > + >>> > define i1 @slt_wrong_offset(i8 %a) { >>> > ; CHECK-LABEL: @slt_wrong_offset( >>> > ; CHECK-NEXT: [[T:%.*]] = add i8 [[A:%.*]], -6 >>> > </cut> >>> >>> -- Maxim Kuvyrkov www.linaro.org _______________________________________________ linaro-toolchain mailing list linaro-toolchain@lists.linaro.org https://lists.linaro.org/mailman/listinfo/linaro-toolchain
