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> _______________________________________________ linaro-toolchain mailing list linaro-toolchain@lists.linaro.org https://lists.linaro.org/mailman/listinfo/linaro-toolchain
