* [PATCH] [PR107608] [range-ops] Avoid folding into INF when flag_trapping_math.
@ 2023-01-15 10:27 Aldy Hernandez
0 siblings, 0 replies; 4+ messages in thread
From: Aldy Hernandez @ 2023-01-15 10:27 UTC (permalink / raw)
To: Jakub Jelinek; +Cc: Richard Biener, Andrew MacLeod, GCC patches, Aldy Hernandez
As discussed in the PR, for trapping math, do not fold overflowing
operations into +-INF as doing so could elide a trap.
There is a minor adjustment to known_isinf() where it was mistakenly
returning true for an [infinity U NAN], whereas it should only return
true when the range is exclusively +INF or -INF. This is benign, as
there were no users of known_isinf up to now.
I had some testsuite issues with:
> FAIL: c-c++-common/diagnostic-format-sarif-file-4.c -std=gnu++14 scan-sarif-file "text": " int \\\\u6587\\\\u5b57\\\\u5316\\\\u3051 =
> FAIL: c-c++-common/diagnostic-format-sarif-file-4.c -std=gnu++17 scan-sarif-file "text": " int \\\\u6587\\\\u5b57\\\\u5316\\\\u3051 =
> FAIL: c-c++-common/diagnostic-format-sarif-file-4.c -std=gnu++20 scan-sarif-file "text": " int \\\\u6587\\\\u5b57\\\\u5316\\\\u3051 =
> FAIL: c-c++-common/diagnostic-format-sarif-file-4.c -std=gnu++98 scan-sarif-file "text": " int \\\\u6587\\\\u5b57\\\\u5316\\\\u3051 =
> FAIL: g++.dg/pr71488.C (test for excess errors)
> FAIL: g++.dg/guality/pr55665.C -O2 -flto -fno-use-linker-plugin -flto-partition=none line 23 p == 40
> FAIL: c-c++-common/diagnostic-format-sarif-file-4.c -Wc++-compat scan-sarif-file "text": " int \\\\u6587\\\\u5b57\\\\u5316\\\\u3051 =
< FAIL: g++.dg/pr71488.C (test for excess errors)
< FAIL: g++.dg/guality/pr55665.C -O2 -flto -fno-use-linker-plugin -flto-partition=none line 23 p == 40
> FAIL: ./index0-out.go execution, -O0 -g -fno-var-tracking-assignments
> FAIL: go.test/test/fixedbugs/issue27836.dir/Äfoo.go -O -I. (test for excess errors)
> FAIL: go.test/test/fixedbugs/issue27836.dir/Ämain.go -O -I. (test for excess errors)
But they seem to be transient issues on my machine, as re-running them
manually don't cause any issues. Also, the tests themselves have
nothing to do with floats so I don't see how they could be related.
Tested on x86-64 Linux.
I also ran the glibc testsuite (git sources) on x86-64 and this patch
fixes:
-FAIL: math/test-double-lgamma
-FAIL: math/test-double-log1p
-FAIL: math/test-float-lgamma
-FAIL: math/test-float-log1p
-FAIL: math/test-float128-catan
-FAIL: math/test-float128-catanh
-FAIL: math/test-float128-lgamma
-FAIL: math/test-float128-log
-FAIL: math/test-float128-log1p
-FAIL: math/test-float128-y0
-FAIL: math/test-float128-y1
-FAIL: math/test-float32-lgamma
-FAIL: math/test-float32-log1p
-FAIL: math/test-float32x-lgamma
-FAIL: math/test-float32x-log1p
-FAIL: math/test-float64-lgamma
-FAIL: math/test-float64-log1p
-FAIL: math/test-float64x-lgamma
-FAIL: math/test-ldouble-lgamma
OK for trunk?
PR tree-optimization/107608
gcc/ChangeLog:
* range-op-float.cc (range_operator_float::fold_range): Avoid
folding into INF when flag_trapping_math.
* value-range.h (frange::known_isinf): Return false for possible NANs.
---
gcc/range-op-float.cc | 21 +++++++++++++++++++++
gcc/value-range.h | 1 +
2 files changed, 22 insertions(+)
diff --git a/gcc/range-op-float.cc b/gcc/range-op-float.cc
index 986a3896a4f..74ac4658378 100644
--- a/gcc/range-op-float.cc
+++ b/gcc/range-op-float.cc
@@ -91,6 +91,27 @@ range_operator_float::fold_range (frange &r, tree type,
else
r.clear_nan ();
+ // If the result has overflowed and flag_trapping_math, folding this
+ // operation could elide an overflow or division by zero exception.
+ // Avoid returning a singleton +-INF, to keep the propagators (DOM
+ // and substitute_and_fold_engine) from folding. See PR107608.
+ if (flag_trapping_math
+ && MODE_HAS_INFINITIES (TYPE_MODE (type))
+ && r.known_isinf () && !op1.known_isinf () && !op2.known_isinf ())
+ {
+ REAL_VALUE_TYPE inf = r.lower_bound ();
+ if (real_isneg (&inf))
+ {
+ REAL_VALUE_TYPE min = real_min_representable (type);
+ r.set (type, inf, min);
+ }
+ else
+ {
+ REAL_VALUE_TYPE max = real_max_representable (type);
+ r.set (type, max, inf);
+ }
+ }
+
return true;
}
diff --git a/gcc/value-range.h b/gcc/value-range.h
index ea50ed3e64a..f4ac73b499f 100644
--- a/gcc/value-range.h
+++ b/gcc/value-range.h
@@ -1300,6 +1300,7 @@ inline bool
frange::known_isinf () const
{
return (m_kind == VR_RANGE
+ && !maybe_isnan ()
&& real_identical (&m_min, &m_max)
&& real_isinf (&m_min));
}
--
2.39.0
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH] [PR107608] [range-ops] Avoid folding into INF when flag_trapping_math.
2023-01-15 12:18 ` Jakub Jelinek
@ 2023-01-15 16:53 ` Aldy Hernandez
0 siblings, 0 replies; 4+ messages in thread
From: Aldy Hernandez @ 2023-01-15 16:53 UTC (permalink / raw)
To: Jakub Jelinek; +Cc: Richard Biener, Andrew MacLeod, GCC patches
On 1/15/23 13:18, Jakub Jelinek wrote:
> On Sun, Jan 15, 2023 at 11:32:27AM +0100, Aldy Hernandez wrote:
>> As discussed in the PR, for trapping math, do not fold overflowing
>> operations into +-INF as doing so could elide a trap.
>>
>> There is a minor adjustment to known_isinf() where it was mistakenly
>> returning true for an [infinity U NAN], whereas it should only return
>> true when the range is exclusively +INF or -INF. This is benign, as
>> there were no users of known_isinf up to now.
>>
>> I had some testsuite issues with:
>>
>>> FAIL: c-c++-common/diagnostic-format-sarif-file-4.c -std=gnu++14 scan-sarif-file "text": " int \\\\u6587\\\\u5b57\\\\u5316\\\\u3051 =
>>> FAIL: c-c++-common/diagnostic-format-sarif-file-4.c -std=gnu++17 scan-sarif-file "text": " int \\\\u6587\\\\u5b57\\\\u5316\\\\u3051 =
>>> FAIL: c-c++-common/diagnostic-format-sarif-file-4.c -std=gnu++20 scan-sarif-file "text": " int \\\\u6587\\\\u5b57\\\\u5316\\\\u3051 =
>>> FAIL: c-c++-common/diagnostic-format-sarif-file-4.c -std=gnu++98 scan-sarif-file "text": " int \\\\u6587\\\\u5b57\\\\u5316\\\\u3051 =
>>> FAIL: g++.dg/pr71488.C (test for excess errors)
>>> FAIL: g++.dg/guality/pr55665.C -O2 -flto -fno-use-linker-plugin -flto-partition=none line 23 p == 40
>>> FAIL: c-c++-common/diagnostic-format-sarif-file-4.c -Wc++-compat scan-sarif-file "text": " int \\\\u6587\\\\u5b57\\\\u5316\\\\u3051 =
>> < FAIL: g++.dg/pr71488.C (test for excess errors)
>> < FAIL: g++.dg/guality/pr55665.C -O2 -flto -fno-use-linker-plugin -flto-partition=none line 23 p == 40
>>> FAIL: ./index0-out.go execution, -O0 -g -fno-var-tracking-assignments
>>> FAIL: go.test/test/fixedbugs/issue27836.dir/Äfoo.go -O -I. (test for excess errors)
>>> FAIL: go.test/test/fixedbugs/issue27836.dir/Ämain.go -O -I. (test for excess errors)
>>
>> But they seem to be transient issues on my machine, as re-running them
>> manually don't cause any issues. Also, the tests themselves have
>> nothing to do with floats so I don't see how they could be related.
>>
>> Tested on x86-64 Linux.
>>
>> I also ran the glibc testsuite (git sources) on x86-64 and this patch
>> fixes:
>>
>> -FAIL: math/test-double-lgamma
>> -FAIL: math/test-double-log1p
>> -FAIL: math/test-float-lgamma
>> -FAIL: math/test-float-log1p
>> -FAIL: math/test-float128-catan
>> -FAIL: math/test-float128-catanh
>> -FAIL: math/test-float128-lgamma
>> -FAIL: math/test-float128-log
>> -FAIL: math/test-float128-log1p
>> -FAIL: math/test-float128-y0
>> -FAIL: math/test-float128-y1
>> -FAIL: math/test-float32-lgamma
>> -FAIL: math/test-float32-log1p
>> -FAIL: math/test-float32x-lgamma
>> -FAIL: math/test-float32x-log1p
>> -FAIL: math/test-float64-lgamma
>> -FAIL: math/test-float64-log1p
>> -FAIL: math/test-float64x-lgamma
>> -FAIL: math/test-ldouble-lgamma
>>
>> OK for trunk?
>>
>> PR tree-optimization/107608
>>
>> gcc/ChangeLog:
>>
>> * range-op-float.cc (range_operator_float::fold_range): Avoid
>> folding into INF when flag_trapping_math.
>> * value-range.h (frange::known_isinf): Return false for possible NANs.
>
> As a workaround this looks ok to me, but we need to figure out something
> better for GCC 14.
Agreed.
I think the underlying problem is that we have little or inconsistent
support for propagating floats. It's not a ranger issue, but all the
levels above it (and even the gimplifier) which seem to do their own
thing wrt when they propagate or not.
FWIW, I still think the issue is DCE and friends which are removing
trapping statements, but I'm happy to entertain other solutions.
Aldy
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH] [PR107608] [range-ops] Avoid folding into INF when flag_trapping_math.
2023-01-15 10:32 Aldy Hernandez
@ 2023-01-15 12:18 ` Jakub Jelinek
2023-01-15 16:53 ` Aldy Hernandez
0 siblings, 1 reply; 4+ messages in thread
From: Jakub Jelinek @ 2023-01-15 12:18 UTC (permalink / raw)
To: Aldy Hernandez; +Cc: Richard Biener, Andrew MacLeod, GCC patches
On Sun, Jan 15, 2023 at 11:32:27AM +0100, Aldy Hernandez wrote:
> As discussed in the PR, for trapping math, do not fold overflowing
> operations into +-INF as doing so could elide a trap.
>
> There is a minor adjustment to known_isinf() where it was mistakenly
> returning true for an [infinity U NAN], whereas it should only return
> true when the range is exclusively +INF or -INF. This is benign, as
> there were no users of known_isinf up to now.
>
> I had some testsuite issues with:
>
> > FAIL: c-c++-common/diagnostic-format-sarif-file-4.c -std=gnu++14 scan-sarif-file "text": " int \\\\u6587\\\\u5b57\\\\u5316\\\\u3051 =
> > FAIL: c-c++-common/diagnostic-format-sarif-file-4.c -std=gnu++17 scan-sarif-file "text": " int \\\\u6587\\\\u5b57\\\\u5316\\\\u3051 =
> > FAIL: c-c++-common/diagnostic-format-sarif-file-4.c -std=gnu++20 scan-sarif-file "text": " int \\\\u6587\\\\u5b57\\\\u5316\\\\u3051 =
> > FAIL: c-c++-common/diagnostic-format-sarif-file-4.c -std=gnu++98 scan-sarif-file "text": " int \\\\u6587\\\\u5b57\\\\u5316\\\\u3051 =
> > FAIL: g++.dg/pr71488.C (test for excess errors)
> > FAIL: g++.dg/guality/pr55665.C -O2 -flto -fno-use-linker-plugin -flto-partition=none line 23 p == 40
> > FAIL: c-c++-common/diagnostic-format-sarif-file-4.c -Wc++-compat scan-sarif-file "text": " int \\\\u6587\\\\u5b57\\\\u5316\\\\u3051 =
> < FAIL: g++.dg/pr71488.C (test for excess errors)
> < FAIL: g++.dg/guality/pr55665.C -O2 -flto -fno-use-linker-plugin -flto-partition=none line 23 p == 40
> > FAIL: ./index0-out.go execution, -O0 -g -fno-var-tracking-assignments
> > FAIL: go.test/test/fixedbugs/issue27836.dir/Äfoo.go -O -I. (test for excess errors)
> > FAIL: go.test/test/fixedbugs/issue27836.dir/Ämain.go -O -I. (test for excess errors)
>
> But they seem to be transient issues on my machine, as re-running them
> manually don't cause any issues. Also, the tests themselves have
> nothing to do with floats so I don't see how they could be related.
>
> Tested on x86-64 Linux.
>
> I also ran the glibc testsuite (git sources) on x86-64 and this patch
> fixes:
>
> -FAIL: math/test-double-lgamma
> -FAIL: math/test-double-log1p
> -FAIL: math/test-float-lgamma
> -FAIL: math/test-float-log1p
> -FAIL: math/test-float128-catan
> -FAIL: math/test-float128-catanh
> -FAIL: math/test-float128-lgamma
> -FAIL: math/test-float128-log
> -FAIL: math/test-float128-log1p
> -FAIL: math/test-float128-y0
> -FAIL: math/test-float128-y1
> -FAIL: math/test-float32-lgamma
> -FAIL: math/test-float32-log1p
> -FAIL: math/test-float32x-lgamma
> -FAIL: math/test-float32x-log1p
> -FAIL: math/test-float64-lgamma
> -FAIL: math/test-float64-log1p
> -FAIL: math/test-float64x-lgamma
> -FAIL: math/test-ldouble-lgamma
>
> OK for trunk?
>
> PR tree-optimization/107608
>
> gcc/ChangeLog:
>
> * range-op-float.cc (range_operator_float::fold_range): Avoid
> folding into INF when flag_trapping_math.
> * value-range.h (frange::known_isinf): Return false for possible NANs.
As a workaround this looks ok to me, but we need to figure out something
better for GCC 14.
Ok for trunk.
Jakub
^ permalink raw reply [flat|nested] 4+ messages in thread
* [PATCH] [PR107608] [range-ops] Avoid folding into INF when flag_trapping_math.
@ 2023-01-15 10:32 Aldy Hernandez
2023-01-15 12:18 ` Jakub Jelinek
0 siblings, 1 reply; 4+ messages in thread
From: Aldy Hernandez @ 2023-01-15 10:32 UTC (permalink / raw)
To: Jakub Jelinek; +Cc: Richard Biener, Andrew MacLeod, GCC patches, Aldy Hernandez
As discussed in the PR, for trapping math, do not fold overflowing
operations into +-INF as doing so could elide a trap.
There is a minor adjustment to known_isinf() where it was mistakenly
returning true for an [infinity U NAN], whereas it should only return
true when the range is exclusively +INF or -INF. This is benign, as
there were no users of known_isinf up to now.
I had some testsuite issues with:
> FAIL: c-c++-common/diagnostic-format-sarif-file-4.c -std=gnu++14 scan-sarif-file "text": " int \\\\u6587\\\\u5b57\\\\u5316\\\\u3051 =
> FAIL: c-c++-common/diagnostic-format-sarif-file-4.c -std=gnu++17 scan-sarif-file "text": " int \\\\u6587\\\\u5b57\\\\u5316\\\\u3051 =
> FAIL: c-c++-common/diagnostic-format-sarif-file-4.c -std=gnu++20 scan-sarif-file "text": " int \\\\u6587\\\\u5b57\\\\u5316\\\\u3051 =
> FAIL: c-c++-common/diagnostic-format-sarif-file-4.c -std=gnu++98 scan-sarif-file "text": " int \\\\u6587\\\\u5b57\\\\u5316\\\\u3051 =
> FAIL: g++.dg/pr71488.C (test for excess errors)
> FAIL: g++.dg/guality/pr55665.C -O2 -flto -fno-use-linker-plugin -flto-partition=none line 23 p == 40
> FAIL: c-c++-common/diagnostic-format-sarif-file-4.c -Wc++-compat scan-sarif-file "text": " int \\\\u6587\\\\u5b57\\\\u5316\\\\u3051 =
< FAIL: g++.dg/pr71488.C (test for excess errors)
< FAIL: g++.dg/guality/pr55665.C -O2 -flto -fno-use-linker-plugin -flto-partition=none line 23 p == 40
> FAIL: ./index0-out.go execution, -O0 -g -fno-var-tracking-assignments
> FAIL: go.test/test/fixedbugs/issue27836.dir/Äfoo.go -O -I. (test for excess errors)
> FAIL: go.test/test/fixedbugs/issue27836.dir/Ämain.go -O -I. (test for excess errors)
But they seem to be transient issues on my machine, as re-running them
manually don't cause any issues. Also, the tests themselves have
nothing to do with floats so I don't see how they could be related.
Tested on x86-64 Linux.
I also ran the glibc testsuite (git sources) on x86-64 and this patch
fixes:
-FAIL: math/test-double-lgamma
-FAIL: math/test-double-log1p
-FAIL: math/test-float-lgamma
-FAIL: math/test-float-log1p
-FAIL: math/test-float128-catan
-FAIL: math/test-float128-catanh
-FAIL: math/test-float128-lgamma
-FAIL: math/test-float128-log
-FAIL: math/test-float128-log1p
-FAIL: math/test-float128-y0
-FAIL: math/test-float128-y1
-FAIL: math/test-float32-lgamma
-FAIL: math/test-float32-log1p
-FAIL: math/test-float32x-lgamma
-FAIL: math/test-float32x-log1p
-FAIL: math/test-float64-lgamma
-FAIL: math/test-float64-log1p
-FAIL: math/test-float64x-lgamma
-FAIL: math/test-ldouble-lgamma
OK for trunk?
PR tree-optimization/107608
gcc/ChangeLog:
* range-op-float.cc (range_operator_float::fold_range): Avoid
folding into INF when flag_trapping_math.
* value-range.h (frange::known_isinf): Return false for possible NANs.
---
gcc/range-op-float.cc | 21 +++++++++++++++++++++
gcc/value-range.h | 1 +
2 files changed, 22 insertions(+)
diff --git a/gcc/range-op-float.cc b/gcc/range-op-float.cc
index 986a3896a4f..74ac4658378 100644
--- a/gcc/range-op-float.cc
+++ b/gcc/range-op-float.cc
@@ -91,6 +91,27 @@ range_operator_float::fold_range (frange &r, tree type,
else
r.clear_nan ();
+ // If the result has overflowed and flag_trapping_math, folding this
+ // operation could elide an overflow or division by zero exception.
+ // Avoid returning a singleton +-INF, to keep the propagators (DOM
+ // and substitute_and_fold_engine) from folding. See PR107608.
+ if (flag_trapping_math
+ && MODE_HAS_INFINITIES (TYPE_MODE (type))
+ && r.known_isinf () && !op1.known_isinf () && !op2.known_isinf ())
+ {
+ REAL_VALUE_TYPE inf = r.lower_bound ();
+ if (real_isneg (&inf))
+ {
+ REAL_VALUE_TYPE min = real_min_representable (type);
+ r.set (type, inf, min);
+ }
+ else
+ {
+ REAL_VALUE_TYPE max = real_max_representable (type);
+ r.set (type, max, inf);
+ }
+ }
+
return true;
}
diff --git a/gcc/value-range.h b/gcc/value-range.h
index ea50ed3e64a..f4ac73b499f 100644
--- a/gcc/value-range.h
+++ b/gcc/value-range.h
@@ -1300,6 +1300,7 @@ inline bool
frange::known_isinf () const
{
return (m_kind == VR_RANGE
+ && !maybe_isnan ()
&& real_identical (&m_min, &m_max)
&& real_isinf (&m_min));
}
--
2.39.0
^ permalink raw reply [flat|nested] 4+ messages in thread
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2023-01-15 10:27 [PATCH] [PR107608] [range-ops] Avoid folding into INF when flag_trapping_math Aldy Hernandez
2023-01-15 10:32 Aldy Hernandez
2023-01-15 12:18 ` Jakub Jelinek
2023-01-15 16:53 ` Aldy Hernandez
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