| Message ID | ZzLlP7nB6MsLdgoO@amerzlyakov-PC |
|---|---|
| State | New |
| Headers | show |
| Series | Fix incorrect subreg mode check [PR117476] | expand |
Updated testsuite/ChangeLog with respect to the original testcase author
-- >8 --
gcc/ChangeLog:
* simplify-rtx.cc (simplify_context::simplify_unary_operation_1):
Fix subreg mode check during zero_extend(not) -> xor optimization.
gcc/testsuite/ChangeLog:
* gcc.dg/pr117476.c: New test. From Zhendong Su.
Signed-off-by: Alexey Merzlyakov <alexey.merzlyakov@samsung.com>
---
gcc/simplify-rtx.cc | 2 +-
gcc/testsuite/gcc.dg/pr117476.c | 12 ++++++++++++
2 files changed, 13 insertions(+), 1 deletion(-)
create mode 100644 gcc/testsuite/gcc.dg/pr117476.c
diff --git a/gcc/simplify-rtx.cc b/gcc/simplify-rtx.cc
index d05efac20dc..2a9cabaad09 100644
--- a/gcc/simplify-rtx.cc
+++ b/gcc/simplify-rtx.cc
@@ -1856,7 +1856,7 @@ simplify_context::simplify_unary_operation_1 (rtx_code code, machine_mode mode,
&& subreg_lowpart_p (op)
&& GET_MODE_SIZE (GET_MODE (op)).is_constant ()
&& (nonzero_bits (XEXP (XEXP (op, 0), 0), mode)
- & ~GET_MODE_MASK (mode)) == 0)
+ & ~GET_MODE_MASK (GET_MODE (op))) == 0)
{
const uint64_t mask = GET_MODE_MASK (GET_MODE (op));
return simplify_gen_binary (XOR, mode,
diff --git a/gcc/testsuite/gcc.dg/pr117476.c b/gcc/testsuite/gcc.dg/pr117476.c
new file mode 100644
index 00000000000..b8f51e697bf
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/pr117476.c
@@ -0,0 +1,12 @@
+/* PR rtl-optimization/117476 */
+/* { dg-do run } */
+/* { dg-options "-O1" } */
+
+int c = 0x1FF;
+
+int main()
+{
+ if (((c ^ 0xFF) & 0xFF) != 0)
+ __builtin_abort();
+ return 0;
+}
Hi Alexey, On 12/11/2024 08:18, Alexey Merzlyakov wrote: > gcc/ChangeLog: > > * simplify-rtx.cc (simplify_context::simplify_unary_operation_1): > Fix subreg mode check during zero_extend(not) -> xor optimization. > > gcc/testsuite/ChangeLog: > > * gcc.dg/pr117476.c: New test. > > Signed-off-by: Alexey Merzlyakov <alexey.merzlyakov@samsung.com> > --- > gcc/simplify-rtx.cc | 2 +- > gcc/testsuite/gcc.dg/pr117476.c | 12 ++++++++++++ > 2 files changed, 13 insertions(+), 1 deletion(-) > create mode 100644 gcc/testsuite/gcc.dg/pr117476.c > > diff --git a/gcc/simplify-rtx.cc b/gcc/simplify-rtx.cc > index d05efac20dc..2a9cabaad09 100644 > --- a/gcc/simplify-rtx.cc > +++ b/gcc/simplify-rtx.cc > @@ -1856,7 +1856,7 @@ simplify_context::simplify_unary_operation_1 (rtx_code code, machine_mode mode, > && subreg_lowpart_p (op) > && GET_MODE_SIZE (GET_MODE (op)).is_constant () > && (nonzero_bits (XEXP (XEXP (op, 0), 0), mode) > - & ~GET_MODE_MASK (mode)) == 0) > + & ~GET_MODE_MASK (GET_MODE (op))) == 0) > { > const uint64_t mask = GET_MODE_MASK (GET_MODE (op)); > return simplify_gen_binary (XOR, mode, > diff --git a/gcc/testsuite/gcc.dg/pr117476.c b/gcc/testsuite/gcc.dg/pr117476.c > new file mode 100644 > index 00000000000..b8f51e697bf > --- /dev/null > +++ b/gcc/testsuite/gcc.dg/pr117476.c I think it might be better to put the test in gcc.c-torture/execute, then it will automatically get run with the various torture options and you should be able to drop both the dejagnu directives. Thanks, Alex > @@ -0,0 +1,12 @@ > +/* PR rtl-optimization/117476 */ > +/* { dg-do run } */ > +/* { dg-options "-O1" } */ > + > +int c = 0x1FF; > + > +int main() > +{ > + if (((c ^ 0xFF) & 0xFF) != 0) > + __builtin_abort(); > + return 0; > +} > -- > 2.34.1
On 11/12/24 4:46 AM, Alex Coplan wrote: > Hi Alexey, > > On 12/11/2024 08:18, Alexey Merzlyakov wrote: >> gcc/ChangeLog: >> >> * simplify-rtx.cc (simplify_context::simplify_unary_operation_1): >> Fix subreg mode check during zero_extend(not) -> xor optimization. >> >> gcc/testsuite/ChangeLog: >> >> * gcc.dg/pr117476.c: New test. >> >> Signed-off-by: Alexey Merzlyakov <alexey.merzlyakov@samsung.com> >> --- >> gcc/simplify-rtx.cc | 2 +- >> gcc/testsuite/gcc.dg/pr117476.c | 12 ++++++++++++ >> 2 files changed, 13 insertions(+), 1 deletion(-) >> create mode 100644 gcc/testsuite/gcc.dg/pr117476.c >> >> diff --git a/gcc/simplify-rtx.cc b/gcc/simplify-rtx.cc >> index d05efac20dc..2a9cabaad09 100644 >> --- a/gcc/simplify-rtx.cc >> +++ b/gcc/simplify-rtx.cc >> @@ -1856,7 +1856,7 @@ simplify_context::simplify_unary_operation_1 (rtx_code code, machine_mode mode, >> && subreg_lowpart_p (op) >> && GET_MODE_SIZE (GET_MODE (op)).is_constant () >> && (nonzero_bits (XEXP (XEXP (op, 0), 0), mode) >> - & ~GET_MODE_MASK (mode)) == 0) >> + & ~GET_MODE_MASK (GET_MODE (op))) == 0) >> { >> const uint64_t mask = GET_MODE_MASK (GET_MODE (op)); >> return simplify_gen_binary (XOR, mode, >> diff --git a/gcc/testsuite/gcc.dg/pr117476.c b/gcc/testsuite/gcc.dg/pr117476.c >> new file mode 100644 >> index 00000000000..b8f51e697bf >> --- /dev/null >> +++ b/gcc/testsuite/gcc.dg/pr117476.c > > I think it might be better to put the test in gcc.c-torture/execute, > then it will automatically get run with the various torture options > and you should be able to drop both the dejagnu directives. Actually, gcc.dg/torture is better. jeff
Hi, Alex, On Tue, Nov 12, 2024 at 11:46:54AM +0000, Alex Coplan wrote: > I think it might be better to put the test in gcc.c-torture/execute, > then it will automatically get run with the various torture options > and you should be able to drop both the dejagnu directives. > > Thanks, > Alex Yep. Now it is going through more options at runtime. Thank you for the suggestion. Updated patch is below: -- >8 -- gcc/ChangeLog: * simplify-rtx.cc (simplify_context::simplify_unary_operation_1): Fix subreg mode check during zero_extend(not) -> xor optimization. gcc/testsuite/ChangeLog: * gcc.c-torture/execute/pr117476.c: New test. From Zhendong Su. Signed-off-by: Alexey Merzlyakov <alexey.merzlyakov@samsung.com> --- gcc/simplify-rtx.cc | 2 +- gcc/testsuite/gcc.c-torture/execute/pr117476.c | 10 ++++++++++ 2 files changed, 11 insertions(+), 1 deletion(-) create mode 100644 gcc/testsuite/gcc.c-torture/execute/pr117476.c diff --git a/gcc/simplify-rtx.cc b/gcc/simplify-rtx.cc index d05efac20dc..2a9cabaad09 100644 --- a/gcc/simplify-rtx.cc +++ b/gcc/simplify-rtx.cc @@ -1856,7 +1856,7 @@ simplify_context::simplify_unary_operation_1 (rtx_code code, machine_mode mode, && subreg_lowpart_p (op) && GET_MODE_SIZE (GET_MODE (op)).is_constant () && (nonzero_bits (XEXP (XEXP (op, 0), 0), mode) - & ~GET_MODE_MASK (mode)) == 0) + & ~GET_MODE_MASK (GET_MODE (op))) == 0) { const uint64_t mask = GET_MODE_MASK (GET_MODE (op)); return simplify_gen_binary (XOR, mode, diff --git a/gcc/testsuite/gcc.c-torture/execute/pr117476.c b/gcc/testsuite/gcc.c-torture/execute/pr117476.c new file mode 100644 index 00000000000..97deb1e2b63 --- /dev/null +++ b/gcc/testsuite/gcc.c-torture/execute/pr117476.c @@ -0,0 +1,10 @@ +/* PR rtl-optimization/117476 */ + +int c = 0x1FF; + +int main() +{ + if (((c ^ 0xFF) & 0xFF) != 0) + __builtin_abort(); + return 0; +}
Hi, Jeff, Oops... It looks like I've made a reply to Alex at the same time when you sent an e-mail update. So, moving the testcase to the gcc.dg/torture directory. On Tue, Nov 12, 2024 at 10:56:13AM -0700, Jeff Law wrote: > > I think it might be better to put the test in gcc.c-torture/execute, > > then it will automatically get run with the various torture options > > and you should be able to drop both the dejagnu directives. > Actually, gcc.dg/torture is better. > > jeff Next version of patch is below: -- >8 -- gcc/ChangeLog: * simplify-rtx.cc (simplify_context::simplify_unary_operation_1): Fix subreg mode check during zero_extend(not) -> xor optimization. gcc/testsuite/ChangeLog: * gcc.dg/torture/pr117476.c: New test. From Zhendong Su. Signed-off-by: Alexey Merzlyakov <alexey.merzlyakov@samsung.com> --- gcc/simplify-rtx.cc | 2 +- gcc/testsuite/gcc.dg/torture/pr117476.c | 11 +++++++++++ 2 files changed, 12 insertions(+), 1 deletion(-) create mode 100644 gcc/testsuite/gcc.dg/torture/pr117476.c diff --git a/gcc/simplify-rtx.cc b/gcc/simplify-rtx.cc index d05efac20dc..2a9cabaad09 100644 --- a/gcc/simplify-rtx.cc +++ b/gcc/simplify-rtx.cc @@ -1856,7 +1856,7 @@ simplify_context::simplify_unary_operation_1 (rtx_code code, machine_mode mode, && subreg_lowpart_p (op) && GET_MODE_SIZE (GET_MODE (op)).is_constant () && (nonzero_bits (XEXP (XEXP (op, 0), 0), mode) - & ~GET_MODE_MASK (mode)) == 0) + & ~GET_MODE_MASK (GET_MODE (op))) == 0) { const uint64_t mask = GET_MODE_MASK (GET_MODE (op)); return simplify_gen_binary (XOR, mode, diff --git a/gcc/testsuite/gcc.dg/torture/pr117476.c b/gcc/testsuite/gcc.dg/torture/pr117476.c new file mode 100644 index 00000000000..7a0225a4f19 --- /dev/null +++ b/gcc/testsuite/gcc.dg/torture/pr117476.c @@ -0,0 +1,11 @@ +/* PR rtl-optimization/117476 */ +/* { dg-do run } */ + +int c = 0x1FF; + +int main() +{ + if (((c ^ 0xFF) & 0xFF) != 0) + __builtin_abort(); + return 0; +}
On 11/12/24 11:31 AM, Alexey Merzlyakov wrote: > Hi, Jeff, > > Oops... It looks like I've made a reply to Alex at the same time when > you sent an e-mail update. > > So, moving the testcase to the gcc.dg/torture directory. > > On Tue, Nov 12, 2024 at 10:56:13AM -0700, Jeff Law wrote: >>> I think it might be better to put the test in gcc.c-torture/execute, >>> then it will automatically get run with the various torture options >>> and you should be able to drop both the dejagnu directives. >> Actually, gcc.dg/torture is better. >> >> jeff > > Next version of patch is below: > > -- >8 -- > > gcc/ChangeLog: > > * simplify-rtx.cc (simplify_context::simplify_unary_operation_1): > Fix subreg mode check during zero_extend(not) -> xor optimization. > > gcc/testsuite/ChangeLog: > > * gcc.dg/torture/pr117476.c: New test. From Zhendong Su. I think we've still got a problem in this code. If we take this test from Zdenek, we completely optimize away foo() during combine. unsigned __int128 g; void foo () { g += __builtin_add_overflow_p (~g, 0, 0ul); } int main () { foo(); if (!g) __builtin_abort(); } $ x86_64-pc-linux-gnu-gcc -O1 testcase.c -Wall -W && ./a.out Aborted I think the problem is the mask we generate when the optimization applies -- and you're about to be exposed to a bit of GCC quirkyness. We've got a TImode ZERO_EXTEND of this object: (gdb) p debug_rtx (op) (subreg:DI (not:TI (reg:TI 100 [ g.0_2 ])) 0) So precisely the kind of case you're trying to handle. This is equivalent to a (xor:TI (reg:TI 100) (const_int 0xffffffffffffffff)) So we end up calling simplify_gen_binary, and our constant is: (gdb) p debug_rtx (op1) (const_int -1 [0xffffffffffffffff]) Note constants in GCC do not have a mode. So that (const_int -1) when interpreted in TImode is 0xffffffffffffffffffffffffffffffff, clearly not what we want. We ultimately return: (gdb) finish Run till exit from #0 simplify_context::simplify_unary_operation_1 (this=0x7fffffffd928, code=ZERO_EXTEND, mode=E_TImode, op=0x7ffff77e5b40) at /home/jlaw/test/gcc/gcc/simplify-rtx.cc:1861 simplify_context::simplify_unary_operation (this=0x7fffffffd928, code=ZERO_EXTEND, mode=E_TImode, op=0x7ffff77e5b40, op_mode=E_DImode) at /home/jlaw/test/gcc/gcc/simplify-rtx.cc:893 893 return simplify_unary_operation_1 (code, mode, op); Value returned is $20 = (rtx_def *) 0x7ffff77c1e20 (gdb) p debug_rtx ($20) (not:TI (reg:TI 100 [ g.0_2 ])) Which is not the same as: (zero_extend:TI (subreg:DI (not:TI (reg:TI 100 [ g.0_2 ])) 0)) Anyway, that the beginning of that function into: (insn 8 6 15 2 (set (reg:TI 107) (not:TI (reg:TI 100 [ g.0_2 ]))) "j.c":6:8 1029 {*one_cmplti2_doubleword} (nil)) (insn 15 8 35 2 (set (reg:TI 108) (not:TI (reg:TI 100 [ g.0_2 ]))) "j.c":6:8 174 {zero_extendditi2} (nil)) (insn 35 15 36 2 (set (reg:CCZ 17 flags) (compare:CCZ (reg:TI 107) (reg:TI 108))) "j.c":6:8 34 {*cmpti_doubleword} (expr_list:REG_DEAD (reg:TI 108) (expr_list:REG_DEAD (reg:TI 107) (nil)))) Naturally things go downhill after that since the condition has a known result, eventually leading to the whole function optimizing away and returning random garbage. So the natural question is how to fix. First I would recommend changing the type of "mask" to a HOST_WIDE_INT. In an of itself that won't fix this problem, but it's the right thing to do. I think what you want is to test HWI_COMPUTABLE_MODE_P. That will verify whether or not the given scalar integer mode can fit into a HOST_WIDE_INT, which should return false for TI or larger modes. Jeff
On Tue, Nov 12, 2024 at 4:43 PM Jeff Law <jeffreyalaw@gmail.com> wrote: > > > > On 11/12/24 11:31 AM, Alexey Merzlyakov wrote: > > Hi, Jeff, > > > > Oops... It looks like I've made a reply to Alex at the same time when > > you sent an e-mail update. > > > > So, moving the testcase to the gcc.dg/torture directory. > > > > On Tue, Nov 12, 2024 at 10:56:13AM -0700, Jeff Law wrote: > >>> I think it might be better to put the test in gcc.c-torture/execute, > >>> then it will automatically get run with the various torture options > >>> and you should be able to drop both the dejagnu directives. > >> Actually, gcc.dg/torture is better. > >> > >> jeff > > > > Next version of patch is below: > > > > -- >8 -- > > > > gcc/ChangeLog: > > > > * simplify-rtx.cc (simplify_context::simplify_unary_operation_1): > > Fix subreg mode check during zero_extend(not) -> xor optimization. > > > > gcc/testsuite/ChangeLog: > > > > * gcc.dg/torture/pr117476.c: New test. From Zhendong Su. > I think we've still got a problem in this code. If we take this test > from Zdenek, we completely optimize away foo() during combine. > > unsigned __int128 g; > > void > foo () > { > g += __builtin_add_overflow_p (~g, 0, 0ul); > } > > int > main () > { > foo(); > if (!g) > __builtin_abort(); > } > $ x86_64-pc-linux-gnu-gcc -O1 testcase.c -Wall -W && ./a.out > Aborted > > I think the problem is the mask we generate when the optimization > applies -- and you're about to be exposed to a bit of GCC quirkyness. > > We've got a TImode ZERO_EXTEND of this object: > > (gdb) p debug_rtx (op) > (subreg:DI (not:TI (reg:TI 100 [ g.0_2 ])) 0) > > > So precisely the kind of case you're trying to handle. This is > equivalent to a (xor:TI (reg:TI 100) (const_int 0xffffffffffffffff)) > > So we end up calling simplify_gen_binary, and our constant is: > > (gdb) p debug_rtx (op1) > (const_int -1 [0xffffffffffffffff]) > > > Note constants in GCC do not have a mode. So that (const_int -1) when > interpreted in TImode is 0xffffffffffffffffffffffffffffffff, clearly not > what we want. We ultimately return: > > (gdb) finish > Run till exit from #0 simplify_context::simplify_unary_operation_1 > (this=0x7fffffffd928, code=ZERO_EXTEND, mode=E_TImode, > op=0x7ffff77e5b40) at /home/jlaw/test/gcc/gcc/simplify-rtx.cc:1861 > simplify_context::simplify_unary_operation (this=0x7fffffffd928, > code=ZERO_EXTEND, mode=E_TImode, op=0x7ffff77e5b40, op_mode=E_DImode) at > /home/jlaw/test/gcc/gcc/simplify-rtx.cc:893 > 893 return simplify_unary_operation_1 (code, mode, op); > Value returned is $20 = (rtx_def *) 0x7ffff77c1e20 > (gdb) p debug_rtx ($20) > (not:TI (reg:TI 100 [ g.0_2 ])) > > > Which is not the same as: > > (zero_extend:TI (subreg:DI (not:TI (reg:TI 100 [ g.0_2 ])) 0)) > > Anyway, that the beginning of that function into: > > (insn 8 6 15 2 (set (reg:TI 107) > (not:TI (reg:TI 100 [ g.0_2 ]))) "j.c":6:8 1029 > {*one_cmplti2_doubleword} > (nil)) > > (insn 15 8 35 2 (set (reg:TI 108) > (not:TI (reg:TI 100 [ g.0_2 ]))) "j.c":6:8 174 {zero_extendditi2} > (nil)) > > (insn 35 15 36 2 (set (reg:CCZ 17 flags) > (compare:CCZ (reg:TI 107) > (reg:TI 108))) "j.c":6:8 34 {*cmpti_doubleword} > (expr_list:REG_DEAD (reg:TI 108) > (expr_list:REG_DEAD (reg:TI 107) > (nil)))) > > Naturally things go downhill after that since the condition has a known > result, eventually leading to the whole function optimizing away and > returning random garbage. > > > So the natural question is how to fix. First I would recommend changing > the type of "mask" to a HOST_WIDE_INT. In an of itself that won't fix > this problem, but it's the right thing to do. I see nonzero_bits returns an unsigned HOST_WIDE_INT; though I wonder if it should use wi::wide_int; maybe it less important for RTX than the gimple level to support wider integers. The places which uses nonzero_bits either use HWI_COMPUTABLE_MODE_P (or ` GET_MODE_PRECISION (int_mode) <= HOST_BITS_PER_WIDE_INT`) or checks against 1 or a had a CONST_INT (which is HWI only). Though I wonder if the ones which check nonzero_bits against 1 are ok. Thanks, Andrew > > I think what you want is to test HWI_COMPUTABLE_MODE_P. That will > verify whether or not the given scalar integer mode can fit into a > HOST_WIDE_INT, which should return false for TI or larger modes. > > Jeff > > > > > > >
On 11/12/24 11:31 AM, Alexey Merzlyakov wrote: > Hi, Jeff, > > Oops... It looks like I've made a reply to Alex at the same time when > you sent an e-mail update. It happens. But as Zdenek's test showed, we've got one more issue to resolve :-) Hopefully my email gave you a solid pointer on what needs adjustment. It didn't even occur to me to worry about TImode constants. jeff
On 12/11/2024 10:56, Jeff Law wrote: > > > On 11/12/24 4:46 AM, Alex Coplan wrote: > > Hi Alexey, > > > > On 12/11/2024 08:18, Alexey Merzlyakov wrote: > > > gcc/ChangeLog: > > > > > > * simplify-rtx.cc (simplify_context::simplify_unary_operation_1): > > > Fix subreg mode check during zero_extend(not) -> xor optimization. > > > > > > gcc/testsuite/ChangeLog: > > > > > > * gcc.dg/pr117476.c: New test. > > > > > > Signed-off-by: Alexey Merzlyakov <alexey.merzlyakov@samsung.com> > > > --- > > > gcc/simplify-rtx.cc | 2 +- > > > gcc/testsuite/gcc.dg/pr117476.c | 12 ++++++++++++ > > > 2 files changed, 13 insertions(+), 1 deletion(-) > > > create mode 100644 gcc/testsuite/gcc.dg/pr117476.c > > > > > > diff --git a/gcc/simplify-rtx.cc b/gcc/simplify-rtx.cc > > > index d05efac20dc..2a9cabaad09 100644 > > > --- a/gcc/simplify-rtx.cc > > > +++ b/gcc/simplify-rtx.cc > > > @@ -1856,7 +1856,7 @@ simplify_context::simplify_unary_operation_1 (rtx_code code, machine_mode mode, > > > && subreg_lowpart_p (op) > > > && GET_MODE_SIZE (GET_MODE (op)).is_constant () > > > && (nonzero_bits (XEXP (XEXP (op, 0), 0), mode) > > > - & ~GET_MODE_MASK (mode)) == 0) > > > + & ~GET_MODE_MASK (GET_MODE (op))) == 0) > > > { > > > const uint64_t mask = GET_MODE_MASK (GET_MODE (op)); > > > return simplify_gen_binary (XOR, mode, > > > diff --git a/gcc/testsuite/gcc.dg/pr117476.c b/gcc/testsuite/gcc.dg/pr117476.c > > > new file mode 100644 > > > index 00000000000..b8f51e697bf > > > --- /dev/null > > > +++ b/gcc/testsuite/gcc.dg/pr117476.c > > > > I think it might be better to put the test in gcc.c-torture/execute, > > then it will automatically get run with the various torture options > > and you should be able to drop both the dejagnu directives. > Actually, gcc.dg/torture is better. Oh, why's that (just so I know for next time)..? Thanks, Alex > > jeff >
On 11/14/24 4:34 AM, Alex Coplan wrote: > On 12/11/2024 10:56, Jeff Law wrote: >> >> >> On 11/12/24 4:46 AM, Alex Coplan wrote: >>> Hi Alexey, >>> >>> On 12/11/2024 08:18, Alexey Merzlyakov wrote: >>>> gcc/ChangeLog: >>>> >>>> * simplify-rtx.cc (simplify_context::simplify_unary_operation_1): >>>> Fix subreg mode check during zero_extend(not) -> xor optimization. >>>> >>>> gcc/testsuite/ChangeLog: >>>> >>>> * gcc.dg/pr117476.c: New test. >>>> >>>> Signed-off-by: Alexey Merzlyakov <alexey.merzlyakov@samsung.com> >>>> --- >>>> gcc/simplify-rtx.cc | 2 +- >>>> gcc/testsuite/gcc.dg/pr117476.c | 12 ++++++++++++ >>>> 2 files changed, 13 insertions(+), 1 deletion(-) >>>> create mode 100644 gcc/testsuite/gcc.dg/pr117476.c >>>> >>>> diff --git a/gcc/simplify-rtx.cc b/gcc/simplify-rtx.cc >>>> index d05efac20dc..2a9cabaad09 100644 >>>> --- a/gcc/simplify-rtx.cc >>>> +++ b/gcc/simplify-rtx.cc >>>> @@ -1856,7 +1856,7 @@ simplify_context::simplify_unary_operation_1 (rtx_code code, machine_mode mode, >>>> && subreg_lowpart_p (op) >>>> && GET_MODE_SIZE (GET_MODE (op)).is_constant () >>>> && (nonzero_bits (XEXP (XEXP (op, 0), 0), mode) >>>> - & ~GET_MODE_MASK (mode)) == 0) >>>> + & ~GET_MODE_MASK (GET_MODE (op))) == 0) >>>> { >>>> const uint64_t mask = GET_MODE_MASK (GET_MODE (op)); >>>> return simplify_gen_binary (XOR, mode, >>>> diff --git a/gcc/testsuite/gcc.dg/pr117476.c b/gcc/testsuite/gcc.dg/pr117476.c >>>> new file mode 100644 >>>> index 00000000000..b8f51e697bf >>>> --- /dev/null >>>> +++ b/gcc/testsuite/gcc.dg/pr117476.c >>> >>> I think it might be better to put the test in gcc.c-torture/execute, >>> then it will automatically get run with the various torture options >>> and you should be able to drop both the dejagnu directives. >> Actually, gcc.dg/torture is better. > > Oh, why's that (just so I know for next time)..? The dg-torture is considered a more modern framework, c-torture is legacy. jeff
diff --git a/gcc/simplify-rtx.cc b/gcc/simplify-rtx.cc index d05efac20dc..2a9cabaad09 100644 --- a/gcc/simplify-rtx.cc +++ b/gcc/simplify-rtx.cc @@ -1856,7 +1856,7 @@ simplify_context::simplify_unary_operation_1 (rtx_code code, machine_mode mode, && subreg_lowpart_p (op) && GET_MODE_SIZE (GET_MODE (op)).is_constant () && (nonzero_bits (XEXP (XEXP (op, 0), 0), mode) - & ~GET_MODE_MASK (mode)) == 0) + & ~GET_MODE_MASK (GET_MODE (op))) == 0) { const uint64_t mask = GET_MODE_MASK (GET_MODE (op)); return simplify_gen_binary (XOR, mode, diff --git a/gcc/testsuite/gcc.dg/pr117476.c b/gcc/testsuite/gcc.dg/pr117476.c new file mode 100644 index 00000000000..b8f51e697bf --- /dev/null +++ b/gcc/testsuite/gcc.dg/pr117476.c @@ -0,0 +1,12 @@ +/* PR rtl-optimization/117476 */ +/* { dg-do run } */ +/* { dg-options "-O1" } */ + +int c = 0x1FF; + +int main() +{ + if (((c ^ 0xFF) & 0xFF) != 0) + __builtin_abort(); + return 0; +}
gcc/ChangeLog: * simplify-rtx.cc (simplify_context::simplify_unary_operation_1): Fix subreg mode check during zero_extend(not) -> xor optimization. gcc/testsuite/ChangeLog: * gcc.dg/pr117476.c: New test. Signed-off-by: Alexey Merzlyakov <alexey.merzlyakov@samsung.com> --- gcc/simplify-rtx.cc | 2 +- gcc/testsuite/gcc.dg/pr117476.c | 12 ++++++++++++ 2 files changed, 13 insertions(+), 1 deletion(-) create mode 100644 gcc/testsuite/gcc.dg/pr117476.c