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