After gcc commit c416c52bcdb120db5e8c53a51bd78c4360daf79b
Author: Nathan Sidwell <[email protected]>
c++ ICE with nested requirement as default tpl parm[PR94827]
the following benchmarks slowed down by more than 2%:
- 456.hmmer slowed down by 4%
Benchmark:
Toolchain: GCC + Glibc + GNU Linker
Version: all components were built from their latest release branch
Target: aarch64-linux-gnu
Compiler flags: -O3 -flto
Hardware: NVidia TX1 4x Cortex-A57
This commit has regressed these CI configurations:
- tcwg_bmk_gnu_tx1/gnu-release-aarch64-spec2k6-O3_LTO
First_bad build:
https://ci.linaro.org/job/tcwg_bmk_ci_gnu-bisect-tcwg_bmk_tx1-gnu-release-aarch64-spec2k6-O3_LTO/43/artifact/artifacts/build-c416c52bcdb120db5e8c53a51bd78c4360daf79b/
Last_good build:
https://ci.linaro.org/job/tcwg_bmk_ci_gnu-bisect-tcwg_bmk_tx1-gnu-release-aarch64-spec2k6-O3_LTO/43/artifact/artifacts/build-b1983f4582bbe060b7da83578acb9ed653681fc8/
Baseline build:
https://ci.linaro.org/job/tcwg_bmk_ci_gnu-bisect-tcwg_bmk_tx1-gnu-release-aarch64-spec2k6-O3_LTO/43/artifact/artifacts/build-baseline/
Even more details:
https://ci.linaro.org/job/tcwg_bmk_ci_gnu-bisect-tcwg_bmk_tx1-gnu-release-aarch64-spec2k6-O3_LTO/43/artifact/artifacts/
Reproduce builds:
<cut>
mkdir investigate-gcc-c416c52bcdb120db5e8c53a51bd78c4360daf79b
cd investigate-gcc-c416c52bcdb120db5e8c53a51bd78c4360daf79b
# Fetch scripts
git clone https://git.linaro.org/toolchain/jenkins-scripts
# Fetch manifests and test.sh script
mkdir -p artifacts/manifests
curl -o artifacts/manifests/build-baseline.sh
https://ci.linaro.org/job/tcwg_bmk_ci_gnu-bisect-tcwg_bmk_tx1-gnu-release-aarch64-spec2k6-O3_LTO/43/artifact/artifacts/manifests/build-baseline.sh
--fail
curl -o artifacts/manifests/build-parameters.sh
https://ci.linaro.org/job/tcwg_bmk_ci_gnu-bisect-tcwg_bmk_tx1-gnu-release-aarch64-spec2k6-O3_LTO/43/artifact/artifacts/manifests/build-parameters.sh
--fail
curl -o artifacts/test.sh
https://ci.linaro.org/job/tcwg_bmk_ci_gnu-bisect-tcwg_bmk_tx1-gnu-release-aarch64-spec2k6-O3_LTO/43/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)
mkdir -p ./bisect
rsync -a --del --delete-excluded --exclude /bisect/ --exclude /artifacts/
--exclude /gcc/ ./ ./bisect/baseline/
cd gcc
# Reproduce first_bad build
git checkout --detach c416c52bcdb120db5e8c53a51bd78c4360daf79b
../artifacts/test.sh
# Reproduce last_good build
git checkout --detach b1983f4582bbe060b7da83578acb9ed653681fc8
../artifacts/test.sh
cd ..
</cut>
Full commit (up to 1000 lines):
<cut>
commit c416c52bcdb120db5e8c53a51bd78c4360daf79b
Author: Nathan Sidwell <[email protected]>
Date: Thu Apr 30 08:23:16 2020 -0700
c++ ICE with nested requirement as default tpl parm[PR94827]
Template headers are not incrementally updated as we parse its parameters.
We maintain a dummy level until the closing > when we replace the dummy with
a real parameter set. requires processing was expecting a properly
populated
arg_vec in current_template_parms, and then creates a self-mapping of
parameters
from that. But we don't need to do that, just teach map_arguments to look
at
TREE_VALUE when args is NULL.
* constraint.cc (map_arguments): If ARGS is null, it's a
self-mapping of parms.
(finish_nested_requirement): Do not pass argified
current_template_parms to normalization.
(tsubst_nested_requirement): Don't assert no template parms.
---
gcc/cp/ChangeLog | 10 ++++++++++
gcc/cp/constraint.cc | 27 ++++++++++++++++-----------
gcc/testsuite/g++.dg/concepts/pr94827.C | 15 +++++++++++++++
3 files changed, 41 insertions(+), 11 deletions(-)
diff --git a/gcc/cp/ChangeLog b/gcc/cp/ChangeLog
index 1fa0e123cb1..3c57945cecf 100644
--- a/gcc/cp/ChangeLog
+++ b/gcc/cp/ChangeLog
@@ -1,3 +1,13 @@
+2020-04-30 Jason Merrill <[email protected]>
+ Nathan Sidwell <[email protected]>
+
+ PR c++/94827
+ * constraint.cc (map_arguments): If ARGS is null, it's a
+ self-mapping of parms.
+ (finish_nested_requirement): Do not pass argified
+ current_template_parms to normalization.
+ (tsubst_nested_requirement): Don't assert no template parms.
+
2020-04-30 Iain Sandoe <[email protected]>
PR c++/94886
diff --git a/gcc/cp/constraint.cc b/gcc/cp/constraint.cc
index 866b0f51b05..85513fecf43 100644
--- a/gcc/cp/constraint.cc
+++ b/gcc/cp/constraint.cc
@@ -546,12 +546,16 @@ static tree
map_arguments (tree parms, tree args)
{
for (tree p = parms; p; p = TREE_CHAIN (p))
- {
- int level;
- int index;
- template_parm_level_and_index (TREE_VALUE (p), &level, &index);
- TREE_PURPOSE (p) = TMPL_ARG (args, level, index);
- }
+ if (args)
+ {
+ int level;
+ int index;
+ template_parm_level_and_index (TREE_VALUE (p), &level, &index);
+ TREE_PURPOSE (p) = TMPL_ARG (args, level, index);
+ }
+ else
+ TREE_PURPOSE (p) = TREE_VALUE (p);
+
return parms;
}
@@ -2005,8 +2009,6 @@ tsubst_compound_requirement (tree t, tree args,
subst_info info)
static tree
tsubst_nested_requirement (tree t, tree args, subst_info info)
{
- gcc_assert (!uses_template_parms (args));
-
/* Ensure that we're in an evaluation context prior to satisfaction. */
tree norm = TREE_VALUE (TREE_TYPE (t));
tree result = satisfy_constraint (norm, args, info);
@@ -2953,12 +2955,15 @@ finish_compound_requirement (location_t loc, tree expr,
tree type, bool noexcept
tree
finish_nested_requirement (location_t loc, tree expr)
{
+ /* Currently open template headers have dummy arg vectors, so don't
+ pass into normalization. */
+ tree norm = normalize_constraint_expression (expr, NULL_TREE, false);
+ tree args = current_template_parms
+ ? template_parms_to_args (current_template_parms) : NULL_TREE;
+
/* Save the normalized constraint and complete set of normalization
arguments with the requirement. We keep the complete set of arguments
around for re-normalization during diagnostics. */
- tree args = current_template_parms
- ? template_parms_to_args (current_template_parms) : NULL_TREE;
- tree norm = normalize_constraint_expression (expr, args, false);
tree info = build_tree_list (args, norm);
/* Build the constraint, saving its normalization as its type. */
diff --git a/gcc/testsuite/g++.dg/concepts/pr94827.C
b/gcc/testsuite/g++.dg/concepts/pr94827.C
new file mode 100644
index 00000000000..f14ec2551a1
--- /dev/null
+++ b/gcc/testsuite/g++.dg/concepts/pr94827.C
@@ -0,0 +1,15 @@
+// PR 94287 ICE looking inside open template-parm level
+// { dg-do run { target c++17 } }
+// { dg-options -fconcepts }
+
+template <typename T,
+ bool X = requires { requires (sizeof(T)==1); } >
+ int foo(T) { return X; }
+
+int main() {
+ if (!foo('4'))
+ return 1;
+ if (foo (4))
+ return 2;
+ return 0;
+}
</cut>
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