This has been fixed in trunk.

On Sun, Oct 3, 2021, 23:02 ci_notify@linaro.org wrote:

[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>