[TCWG CI] Regression caused by gcc: [PR102546] X << Y being non-zero implies X is also non-zero.: commit 5f9ccf17de7f7581412c6bffd4a37beca9a79836 Author: Aldy Hernandez aldyh@redhat.com
[PR102546] X << Y being non-zero implies X is also non-zero.
Results regressed to # reset_artifacts: -10 # build_abe binutils: -9 # build_abe stage1: -5 # build_abe qemu: -2 # linux_n_obj: 18603 # First few build errors in logs: # 00:01:53 arch/arm/vfp/vfpdouble.c:1206:1: internal compiler error: in upper_bound, at value-range.h:531 # 00:01:53 arch/arm/vfp/vfpsingle.c:1246:1: internal compiler error: in upper_bound, at value-range.h:531 # 00:01:53 make[2]: *** [scripts/Makefile.build:271: arch/arm/vfp/vfpdouble.o] Error 1 # 00:01:54 make[2]: *** [scripts/Makefile.build:271: arch/arm/vfp/vfpsingle.o] Error 1 # 00:01:55 make[1]: *** [scripts/Makefile.build:514: arch/arm/vfp] Error 2 # 00:01:56 arch/arm/nwfpe/softfloat.c:3432:1: internal compiler error: in upper_bound, at value-range.h:531 # 00:01:57 make[2]: *** [scripts/Makefile.build:271: arch/arm/nwfpe/softfloat.o] Error 1 # 00:01:57 make[1]: *** [scripts/Makefile.build:514: arch/arm/nwfpe] Error 2 # 00:02:14 arch/arm/kernel/smp.c:857:1: internal compiler error: in upper_bound, at value-range.h:531 # 00:02:15 make[2]: *** [scripts/Makefile.build:271: arch/arm/kernel/smp.o] Error 1
from # reset_artifacts: -10 # build_abe binutils: -9 # build_abe stage1: -5 # build_abe qemu: -2 # linux_n_obj: 19709 # linux build successful: all
THIS IS THE END OF INTERESTING STUFF. BELOW ARE LINKS TO BUILDS, REPRODUCTION INSTRUCTIONS, AND THE RAW COMMIT.
This commit has regressed these CI configurations: - tcwg_kernel/gnu-master-arm-stable-allyesconfig
First_bad build: https://ci.linaro.org/job/tcwg_kernel-gnu-bisect-gnu-master-arm-stable-allye... Last_good build: https://ci.linaro.org/job/tcwg_kernel-gnu-bisect-gnu-master-arm-stable-allye... Baseline build: https://ci.linaro.org/job/tcwg_kernel-gnu-bisect-gnu-master-arm-stable-allye... Even more details: https://ci.linaro.org/job/tcwg_kernel-gnu-bisect-gnu-master-arm-stable-allye...
Reproduce builds: <cut> mkdir investigate-gcc-5f9ccf17de7f7581412c6bffd4a37beca9a79836 cd investigate-gcc-5f9ccf17de7f7581412c6bffd4a37beca9a79836
# 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_kernel-gnu-bisect-gnu-master-arm-stable-allye... --fail curl -o artifacts/manifests/build-parameters.sh https://ci.linaro.org/job/tcwg_kernel-gnu-bisect-gnu-master-arm-stable-allye... --fail curl -o artifacts/test.sh https://ci.linaro.org/job/tcwg_kernel-gnu-bisect-gnu-master-arm-stable-allye... --fail chmod +x artifacts/test.sh
# Reproduce the baseline build (build all pre-requisites) ./jenkins-scripts/tcwg_kernel-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 5f9ccf17de7f7581412c6bffd4a37beca9a79836 ../artifacts/test.sh
# Reproduce last_good build git checkout --detach 257d2890a769a8aa564d079170377e637e07acb1 ../artifacts/test.sh
cd .. </cut>
Full commit (up to 1000 lines): <cut> commit 5f9ccf17de7f7581412c6bffd4a37beca9a79836 Author: Aldy Hernandez aldyh@redhat.com Date: Fri Oct 1 13:05:36 2021 +0200
[PR102546] X << Y being non-zero implies X is also non-zero.
This patch teaches this to range-ops.
Tested on x86-64 Linux.
gcc/ChangeLog:
PR tree-optimization/102546 * range-op.cc (operator_lshift::op1_range): Teach range-ops that X << Y is non-zero implies X is also non-zero. --- gcc/range-op.cc | 18 ++++++++++++++---- gcc/testsuite/gcc.dg/tree-ssa/pr102546.c | 23 +++++++++++++++++++++++ 2 files changed, 37 insertions(+), 4 deletions(-)
diff --git a/gcc/range-op.cc b/gcc/range-op.cc index 5e37133026d..2baca4a197f 100644 --- a/gcc/range-op.cc +++ b/gcc/range-op.cc @@ -2078,6 +2078,12 @@ operator_lshift::op1_range (irange &r, relation_kind rel ATTRIBUTE_UNUSED) const { tree shift_amount; + + if (!lhs.contains_p (build_zero_cst (type))) + r.set_nonzero (type); + else + r.set_varying (type); + if (op2.singleton_p (&shift_amount)) { wide_int shift = wi::to_wide (shift_amount); @@ -2089,21 +2095,24 @@ operator_lshift::op1_range (irange &r, return false; if (shift == 0) { - r = lhs; + r.intersect (lhs); return true; }
// Work completely in unsigned mode to start. tree utype = type; + int_range_max tmp_range; if (TYPE_SIGN (type) == SIGNED) { int_range_max tmp = lhs; utype = unsigned_type_for (type); range_cast (tmp, utype); - op_rshift.fold_range (r, utype, tmp, op2); + op_rshift.fold_range (tmp_range, utype, tmp, op2); } else - op_rshift.fold_range (r, utype, lhs, op2); + op_rshift.fold_range (tmp_range, utype, lhs, op2); + + r.intersect (tmp_range);
// Start with ranges which can produce the LHS by right shifting the // result by the shift amount. @@ -2128,7 +2137,8 @@ operator_lshift::op1_range (irange &r, range_cast (r, type); return true; } - return false; + + return !r.varying_p (); }
bool diff --git a/gcc/testsuite/gcc.dg/tree-ssa/pr102546.c b/gcc/testsuite/gcc.dg/tree-ssa/pr102546.c new file mode 100644 index 00000000000..4bd98747732 --- /dev/null +++ b/gcc/testsuite/gcc.dg/tree-ssa/pr102546.c @@ -0,0 +1,23 @@ +// { dg-do compile } +// { dg-options "-O3 -fdump-tree-optimized" } + +static int a; +static char b, c, d; +void bar(void); +void foo(void); + +int main() { + int f = 0; + for (; f <= 5; f++) { + bar(); + b = b && f; + d = f << f; + if (!(a >= d || f)) + foo(); + c = 1; + for (; c; c = 0) + ; + } +} + +// { dg-final { scan-tree-dump-not "foo" "optimized" } } </cut>