Successfully identified regression in *gcc* in CI configuration tcwg_gnu/gnu-master-arm-check_bootstrap. So far, this commit has regressed CI configurations: - tcwg_gnu/gnu-master-arm-check_bootstrap

Culprit: <cut> commit 8a8a7d332d5d01db5aea7336a36d9fd71a679fb1 Author: Ian Lance Taylor iant@golang.org Date: Mon Jun 28 16:47:55 2021 -0700

compiler: in composite literals use temps only for interfaces

For a composite literal we only need to introduce a temporary variable if we may be converting to an interface type, so only do it then. This saves over 80% of compilation time when using gccgo to compile cmd/internal/obj/x86, as the GCC middle-end spends a lot of time pointlessly computing interactions between temporary variables.

For PR debug/101064 For golang/go#46600

Reviewed-on: https://go-review.googlesource.com/c/gofrontend/+/331513 </cut>

Results regressed to (for first_bad == 8a8a7d332d5d01db5aea7336a36d9fd71a679fb1) # reset_artifacts: -10 # build_abe bootstrap: 0 # build_abe check_bootstrap: 1 # # Comparing directories # # REFERENCE: base-artifacts/sumfiles # # CURRENT: /home/tcwg-buildslave/workspace/tcwg_gnu_2/artifacts/build-8a8a7d332d5d01db5aea7336a36d9fd71a679fb1/sumfiles # # # Comparing 12 common sum files: # g++.sum # gcc.sum # gfortran.sum # go.sum # gotools.sum # libatomic.sum # libffi.sum # libgo.sum # libgomp.sum # libitm.sum # libstdc++.sum # objc.sum # Comparing: # REFERENCE:/tmp/gxx-sum1.1601595 # CURRENT: /tmp/gxx-sum2.1601595 # # ` +---------+---------+ # o RUN STATUS: | REF | RES | # +------------------------------------------+---------+---------+ # | Passes [PASS] | 460522 | 460519 | # | Unexpected fails [FAIL] | 194 | 197 | # | Errors [ERROR] | 0 | 0 | # | Unexpected passes [XPASS] | 15 | 15 | # | Expected fails [XFAIL] | 2737 | 2737 | # | Unresolved [UNRESOLVED] | 104 | 104 | # | Unsupported [UNSUPPORTED] | 22896 | 22896 | # | Untested [UNTESTED] | 10 | 10 | # +------------------------------------------+---------+---------+ # # REF PASS ratio: 0.952271 # RES PASS ratio: 0.952265 # # o REGRESSIONS: # +------------------------------------------+---------+ # | PASS now FAIL [PASS => FAIL] | 3 | # +------------------------------------------+---------+ # | TOTAL_REGRESSIONS | 3 | # +------------------------------------------+---------+ # # - PASS now FAIL [PASS => FAIL]: # # Executed from: go.test/go-test.exp # go:go.test/test/fixedbugs/issue19182.go execution, -O2 -g # Executed from: /home/tcwg-buildslave/workspace/tcwg_gnu_2/abe/snapshots/gcc.git~master/libgo/libgo.exp # libgo:os/signal # libgo:sync/atomic # # # # o IMPROVEMENTS TO BE CHECKED: # +------------------------------------------+---------+ # +------------------------------------------+---------+ # | TOTAL_IMPROVEMENTS_TO_BE_CHECKED | 0 | # +------------------------------------------+---------+ # # # # Regressions found # # Regressions in 12 common sum files found

from (for last_good == c60d9160b4d966dbea5b1bbea4f817c64d0bee2d) # reset_artifacts: -10 # build_abe bootstrap: 0 # build_abe check_bootstrap: 1

Artifacts of last_good build: https://ci.linaro.org/job/tcwg_gcc-bisect-gnu-master-arm-check_bootstrap/72/... Artifacts of first_bad build: https://ci.linaro.org/job/tcwg_gcc-bisect-gnu-master-arm-check_bootstrap/72/... Build top page/logs: https://ci.linaro.org/job/tcwg_gcc-bisect-gnu-master-arm-check_bootstrap/72/

Configuration details:

Reproduce builds: <cut> mkdir investigate-gcc-8a8a7d332d5d01db5aea7336a36d9fd71a679fb1 cd investigate-gcc-8a8a7d332d5d01db5aea7336a36d9fd71a679fb1

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_gcc-bisect-gnu-master-arm-check_bootstrap/72/... --fail curl -o artifacts/manifests/build-parameters.sh https://ci.linaro.org/job/tcwg_gcc-bisect-gnu-master-arm-check_bootstrap/72/... --fail curl -o artifacts/test.sh https://ci.linaro.org/job/tcwg_gcc-bisect-gnu-master-arm-check_bootstrap/72/... --fail chmod +x artifacts/test.sh

# Reproduce the baseline build (build all pre-requisites) ./jenkins-scripts/tcwg_gnu-build.sh @@ artifacts/manifests/build-baseline.sh

cd gcc

# Reproduce first_bad build git checkout --detach 8a8a7d332d5d01db5aea7336a36d9fd71a679fb1 ../artifacts/test.sh

# Reproduce last_good build git checkout --detach c60d9160b4d966dbea5b1bbea4f817c64d0bee2d ../artifacts/test.sh

cd .. </cut>

History of pending regressions and results: https://git.linaro.org/toolchain/ci/base-artifacts.git/log/?h=linaro-local/c...

Artifacts: https://ci.linaro.org/job/tcwg_gcc-bisect-gnu-master-arm-check_bootstrap/72/... Build log: https://ci.linaro.org/job/tcwg_gcc-bisect-gnu-master-arm-check_bootstrap/72/...

Full commit (up to 1000 lines): <cut> commit 8a8a7d332d5d01db5aea7336a36d9fd71a679fb1 Author: Ian Lance Taylor iant@golang.org Date: Mon Jun 28 16:47:55 2021 -0700

compiler: in composite literals use temps only for interfaces

For a composite literal we only need to introduce a temporary variable if we may be converting to an interface type, so only do it then. This saves over 80% of compilation time when using gccgo to compile cmd/internal/obj/x86, as the GCC middle-end spends a lot of time pointlessly computing interactions between temporary variables.

For PR debug/101064 For golang/go#46600

Reviewed-on: https://go-review.googlesource.com/c/gofrontend/+/331513 --- gcc/go/gofrontend/MERGE | 2 +- gcc/go/gofrontend/expressions.cc | 17 +++++++++++++---- 2 files changed, 14 insertions(+), 5 deletions(-)

diff --git a/gcc/go/gofrontend/MERGE b/gcc/go/gofrontend/MERGE index f16fb9facc3..f7bcc8c484a 100644 --- a/gcc/go/gofrontend/MERGE +++ b/gcc/go/gofrontend/MERGE @@ -1,4 +1,4 @@ -bcafcb3c39530bb325514d6377747eb3127d1a03 +cad187fe3aceb2a7d964b64c70dfa8c8ad24ce65

The first line of this file holds the git revision number of the last merge done from the gofrontend repository. diff --git a/gcc/go/gofrontend/expressions.cc b/gcc/go/gofrontend/expressions.cc index 5d45e4baab4..94342b2f9b8 100644 --- a/gcc/go/gofrontend/expressions.cc +++ b/gcc/go/gofrontend/expressions.cc @@ -15148,7 +15148,7 @@ Struct_construction_expression::do_copy() }

// Flatten a struct construction expression. Store the values into -// temporaries in case they need interface conversion. +// temporaries if they may need interface conversion.

Expression* Struct_construction_expression::do_flatten(Gogo*, Named_object*, @@ -15162,10 +15162,13 @@ Struct_construction_expression::do_flatten(Gogo*, Named_object*, return this;

Location loc = this->location(); + const Struct_field_list* fields = this->type_->struct_type()->fields(); + Struct_field_list::const_iterator pf = fields->begin(); for (Expression_list::iterator pv = this->vals()->begin(); pv != this->vals()->end(); - ++pv) + ++pv, ++pf) { + go_assert(pf != fields->end()); if (*pv != NULL) { if ((*pv)->is_error_expression() || (*pv)->type()->is_error_type()) @@ -15173,7 +15176,8 @@ Struct_construction_expression::do_flatten(Gogo*, Named_object*, go_assert(saw_errors()); return Expression::make_error(loc); } - if (!(*pv)->is_multi_eval_safe()) + if (pf->type()->interface_type() != NULL + && !(*pv)->is_multi_eval_safe()) { Temporary_statement* temp = Statement::make_temporary(NULL, *pv, loc); @@ -15448,7 +15452,7 @@ Array_construction_expression::do_check_types(Gogo*) }

// Flatten an array construction expression. Store the values into -// temporaries in case they need interface conversion. +// temporaries if they may need interface conversion.

Expression* Array_construction_expression::do_flatten(Gogo*, Named_object*, @@ -15467,6 +15471,11 @@ Array_construction_expression::do_flatten(Gogo*, Named_object*, if (this->is_constant_array() || this->is_static_initializer()) return this;

+ // If the array element type is not an interface type, we don't need + // temporaries. + if (this->type_->array_type()->element_type()->interface_type() == NULL) + return this; + Location loc = this->location(); for (Expression_list::iterator pv = this->vals()->begin(); pv != this->vals()->end(); </cut>