ink a
distinction between evaluating at compile time or at run time can't be
observed.
Agreed.
Can't be observed might be a bit strong?
constexpr int f(){
if consteval {return 1;} else {return 2;}
}
int main(){
int a=f();
const int b=f();
return a+b;
}
returns 3 (and clang agrees).
--
Marc Glisse
ven when asked to execute
nonsense.
(things would obviously be different if the standard standardized the
no-op behavior on these specific functions)
--
Marc Glisse
@3 @4))
(cnd @0 (op! @1 @3) (op! @2 @4)
?
The example given in the doc for the use of '!' is pretty close
@smallexample
(simplify
(plus (vec_cond:s @@0 @@1 @@2) @@3)
(vec_cond @@0 (plus! @@1 @@3) (plus! @@2 @@3)))
@end smallexample
--
Marc Glisse
o
fold X<=Y and if it folds to true then simplifies to Y. This way the
transformations would only need to be written for comparisons, not minmax.
--
Marc Glisse
was optimized to just one call to calloc (someone broke that in gcc-10).
Using LTO on libsupc++ is related.
I don't know if we want to define "sane" operators new/delete, or just
have a flag that promises that we won't try to replace the default ones.
--
Marc Glisse
On Tue, 21 Nov 2023, Jonathan Wakely wrote:
CC Marc Glisse who added the relocation support. He might recall why
we use memmove when all uses are for newly-allocated storage, which
cannot overlap the existing storage.
Going back a bit:
https://gcc.gnu.org/pipermail/gcc-patches/2019-April
like the criterion would be a|(b&c) when the possible 1 bits of b
are included in the certainly 1 bits of a|c.
--
Marc Glisse
call SIMD intrinsics/builtins
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=80517 and others.
Makes sense to work around them for now.
--
Marc Glisse
traits where you can save
several instantiations. Now that you have done a couple simple cases to
see how it works, I think you should concentrate on the more complicated
cases.
--
Marc Glisse
y shuffles?
--
Marc Glisse
ined."
To me, this means that for instance INT_MIN<<1 is well defined and
evaluates to 0. But with this patch we turn (INT_MIN<<1)+(INT_MIN<<1) into
(INT_MIN+INT_MIN)<<1, which is UB.
If we decide not to support this extension anymore, I think we need to
change the documentation first.
--
Marc Glisse
On Thu, 31 Mar 2022, Jonathan Wakely wrote:
On Thu, 31 Mar 2022 at 17:03, Marc Glisse via Libstdc++
wrote:
On Thu, 31 Mar 2022, Matthias Kretz via Gcc-patches wrote:
I like it. But I'd like it even more if we could have
#elif defined _UBSAN
__ubsan_invoke_ub("reached std::u
right subset of) ubsan is enabled sounds like a
good idea.
--
Marc Glisse
zed at vector lowering time.
+/* Push VEC_PERM earlier if that may help FMA perception (PR101895). */
+(for plusminus (plus minus)
+ (simplify
+(plusminus (vec_perm (mult@0 @1 vec_same_elem_p@2) @0 @3) @4)
+(plusminus (mult (vec_perm @1 @1 @3) @2) @4)))
Don't you want :s on mult and vec_perm?
--
Marc Glisse
IFN_FMIN bit_and bit_ior bit_xor)
+ (simplify (reduc (op @0 VECTOR_CST@1))
+(op (reduc:type @0) (reduc:type @1
I wonder if we need to test flag_associative_math for the 'plus' case,
or if the presence of IFN_REDUC_PLUS is enough to justify the possible
loss of precision.
--
Marc Glisse
eans :-(
(sorry for the broken thread, I was automatically unsubscribed because
mailman doesn't like greylisting)
--
Marc Glisse
s like it could be part of a separate
compiler flag or pragma, like C's FENV_ROUND can affect the rounding mode
in static initializers (of course C++ templates make pragmas less
convenient).
--
Marc Glisse
at's being worked on right now.
I've also added some extra tests to cover this new pattern. I've attached a
patch with my latest changes.
From: Richard Biener
Sent: Wednesday, July 28, 2021 2:59 AM
To: Victor Tong
Cc: Marc Glisse ; gcc-patches@gcc.gnu.org
Subject: Re: [EXT
) & tree_nonzero_bits (@4)) == 0)
+ (mult @1
+{ wide_int_to_tree (type, wi::to_wide (@3) + wi::to_wide (@5)); })))
Could you explain how the convert helps exactly?
--
Marc Glisse
es of each @i is not
reliable.
--
Marc Glisse
y try to see a pattern
in the list of types that work)
--
Marc Glisse
On Fri, 4 Jun 2021, Hongtao Liu via Gcc-patches wrote:
On Tue, Jun 1, 2021 at 6:17 PM Marc Glisse wrote:
On Tue, 1 Jun 2021, Hongtao Liu via Gcc-patches wrote:
Hi:
This patch is about to simplify (view_convert:type ~a) < 0 to
(view_convert:type a) >= 0 when type is signed integer. S
ense to try and generalize it a bit, say with
(cmp (nop_convert1? (bit_not @0)) CONSTANT_CLASS_P)
(scmp (view_convert:XXX @0) (bit_not @1))
(I still believe that it is a bad idea that SSA_NAMEs are strongly typed,
encoding the type in operations would be more convenient, but I think the
time for that choice has long gone)
--
Marc Glisse
On Wed, 26 May 2021, Prathamesh Kulkarni via Gcc-patches wrote:
The attached patch removes calls to builtins in vmul_n* (a, b) with __a * __b.
I am not familiar with neon, but are __a and __b unsigned here? Otherwise,
is vmul_n already undefined in case of overflow?
--
Marc Glisse
E_P (TREE_TYPE (@0))
+&& !TYPE_UNSIGNED (TREE_TYPE (@0))
+&& TYPE_PRECISION (TREE_TYPE (@0)) == TYPE_PRECISION (type))
Is there a risk that x is signed char (precision 8) and y is a vector with
8 elements?
--
Marc Glisse
On Fri, 14 May 2021, Jakub Jelinek via Gcc-patches wrote:
On Thu, May 06, 2021 at 09:42:41PM +0200, Marc Glisse wrote:
We can probably do it in 2 steps, first something like
(for cmp (eq ne)
(simplify
(cmp (bit_and:c @0 @1) @0)
(cmp (@0 (bit_not! @1)) { build_zero_cst (TREE_TYPE (@0
On Tue, 11 May 2021, Jakub Jelinek via Gcc-patches wrote:
On Thu, May 06, 2021 at 09:42:41PM +0200, Marc Glisse wrote:
We can probably do it in 2 steps, first something like
(for cmp (eq ne)
(simplify
(cmp (bit_and:c @0 @1) @0)
(cmp (@0 (bit_not! @1)) { build_zero_cst (TREE_TYPE (@0
though if X is signed, the
way GIMPLE represents types will add an inconvenient cast. And I think VRP
already manages to use the bit test to derive a range.
--
Marc Glisse
should be
unreachable and so (_M_value&1)==_M_value is then equivalent to _M_value>=0,
but is not a single use but two uses. I'll need to pattern match that case
specially.
Somewhere in RTL (_M_value&1)==_M_value is turned into (_M_value&-2)==0,
that could be worth doing already in GIMPLE.
--
Marc Glisse
this particular transformation (don't change the patch
because of my comment), we just seem to be getting more and more uses of
single_use in match.pd, maybe at some point we need to revisit the meaning
of :s or introduce a stronger :S.
--
Marc Glisse
g the same directory for
linking should imply using the same directory for includes.
--
Marc Glisse
On Sat, 12 Dec 2020, Jakub Jelinek via Gcc-patches wrote:
On Sat, Dec 12, 2020 at 01:25:39PM +0100, Marc Glisse wrote:
On Sat, 12 Dec 2020, Jakub Jelinek via Gcc-patches wrote:
This patch adds the ~(X - Y) -> ~X + Y simplification requested
in the PR (plus also ~(X + C) -> ~X + (-
d then extending it to non-constants)?
I wonder if this makes
/* ~(~X - Y) -> X + Y and ~(~X + Y) -> X - Y. */
useless.
--
Marc Glisse
ld succeed if either overflow
is undefined or if VRP can prove that no overflow is happening.
Of course that's all ideas for later, refactoring belongs in the second or
third patch using a feature, not the first one :-)
--
Marc Glisse
lt; MIN(X, Y) -> false
So, the result will be true for GE_EXPR and LE_EXPR and false otherwise.
Is that true even if X is NaN?
It may be hard to hit a situation where this matters though, if we honor
NaN, we don't build MAX_EXPR (which is unspecified).
--
Marc Glisse
On Wed, 2 Sep 2020, Jason Merrill via Gcc-patches wrote:
On 9/1/20 6:13 AM, Marc Glisse wrote:
On Tue, 1 Sep 2020, Jakub Jelinek via Gcc-patches wrote:
As discussed in the PR, fold-const.c punts on floating point constant
evaluation if the result is inexact and -frounding-math is turned on
s in
tree-vect-generic.c using V_C_Es looks much safer to me.
If they weren't so rare, we could consider lowering them earlier so they
benefit from more optimizations, but that doesn't seem worth the trouble.
--
Marc Glisse
&&f = 0x1.0p+100 + 0x1.0p-100;
+ static_assert (0x1.0p+100 + 0x1.0p-100 == 0x1.0p+100, "");
+}
+
+const double &g = a;
+const double &h = b;
Jakub
--
Marc Glisse
On Sat, 22 Aug 2020, Jonathan Wakely via Gcc-patches wrote:
On Sat, 22 Aug 2020 at 13:13, Jonathan Wakely wrote:
On Sat, 22 Aug 2020 at 10:52, Marc Glisse wrote:
is there a particular reason to handle only __int128 this way, and not all
the non-standard integer types? It looks like it would
_8 = (unsigned int) x_4(D);
_9 = _8 >> 16;
_10 = (int) _9;
_2 = __builtin_bswap16 (_10);
_3 = _1 | _2;
_5 = (int) _3;
return _5;
}
Handling this in the same transformation with a pair of convert12? and
some tests should be doable, but it gets complicated enough that it is
fine to postpone that.
--
Marc Glisse
gets, there
is an intermediate extension, and 16 bit targets are "rare"? And
BUILT_IN_BSWAP128 because on most platforms intmax_t is only 64 bits and
we don't have a 128-bit version of parity/popcount? (we have an IFN, but
it seldom appears by magic)
--
Marc Glisse
is there a particular reason to handle only __int128 this way, and not all
the non-standard integer types? It looks like it would be a bit simpler to
avoid a special case.
--
Marc Glisse
kept this useless bit_and when casting to a smaller
type. We probably get a different pattern on 16-bit targets, but a pattern
they do not match won't hurt them.
--
Marc Glisse
Odd numbers are invertible in Z / 2^n Z, so X * C1 == C2 can be rewritten
as X == C2 * inv(C1) when overflow wraps.
mod_inv should probably be updated to better match the other wide_int
functions, but that's a separate issue.
Bootstrap+regtest on x86_64-pc-linux-gnu.
2020-08-10 Marc G
On Fri, 7 Aug 2020, Jakub Jelinek wrote:
On Fri, Aug 07, 2020 at 10:57:54PM +0200, Marc Glisse wrote:
On Fri, 7 Aug 2020, Joern Wolfgang Rennecke wrote:
On 07/08/20 19:21, Marc Glisse wrote:
If we are going to handle the wrapping case, we shouldn't limit to
the non-wrapping meani
On Fri, 7 Aug 2020, Joern Wolfgang Rennecke wrote:
On 07/08/20 19:21, Marc Glisse wrote:
If we are going to handle the wrapping case, we shouldn't limit to the
non-wrapping meaning of multiplicity. 3*X==5 should become X==1431655767
(for a 32 bit type), etc.
Do we have an extende
but we don't have to limit to the case where 15 is a multiple of 3. 3*X>7
can be replaced with X>2.
Those are two nice suggestions. Do you intend to write a patch? Otherwise
I'll try to do it eventually (no promise).
--
Marc Glisse
ound
from a fake global variable instead of a function call) would be tempting,
but it doesn't work, since now .FENV_PLUS can migrate after a later call
to fesetround. Even without exceptions we need some protection after, so
it may be easier to keep the memory (fenv) read as part of .FENV_PLUS.
Also, caring only about rounding doesn't match any standard #pragma, so
such an option may see very little use in practice...
Sorry for the incoherent brain-dump above ;)
It is great to have someone to discuss this with!
--
Marc Glisse
On Fri, 7 Aug 2020, Richard Biener wrote:
On Fri, Aug 7, 2020 at 10:33 AM Marc Glisse wrote:
On Fri, 7 Aug 2020, Richard Biener wrote:
On Thu, Aug 6, 2020 at 8:07 PM Marc Glisse wrote:
On Thu, 6 Aug 2020, Christophe Lyon wrote:
Was I on the right track configuring with
--target=arm
d whether we can simplify or not is
something that depends on each operation (what the pragma said at that
point in the source code), while flag_finite_math_only is at best per
function.
--
Marc Glisse
On Fri, 7 Aug 2020, Richard Biener wrote:
On Thu, Aug 6, 2020 at 8:07 PM Marc Glisse wrote:
On Thu, 6 Aug 2020, Christophe Lyon wrote:
Was I on the right track configuring with
--target=arm-none-linux-gnueabihf --with-cpu=cortex-a9
--with-fpu=neon-fp16
then compiling without any special
patch, but I would like it to be temporary.
Since aarch64 seems to handle the same code just fine, maybe someone who
knows arm could copy the relevant code over?
Does my message make sense, do people have comments?
--
Marc Glisse
On Thu, 6 Aug 2020, Christophe Lyon wrote:
On Thu, 6 Aug 2020 at 11:06, Marc Glisse wrote:
On Thu, 6 Aug 2020, Christophe Lyon wrote:
2020-08-05 Marc Glisse
PR tree-optimization/95906
PR target/70314
* match.pd ((c ? a : b) op d, (c ? a : b) op (c ? d : e
On Thu, 6 Aug 2020, Richard Biener wrote:
On Thu, Aug 6, 2020 at 10:17 AM Christophe Lyon
wrote:
Hi,
On Wed, 5 Aug 2020 at 16:24, Richard Biener via Gcc-patches
wrote:
On Wed, Aug 5, 2020 at 3:33 PM Marc Glisse wrote:
New version that passed bootstrap+regtest during the night.
When
On Thu, 6 Aug 2020, Christophe Lyon wrote:
2020-08-05 Marc Glisse
PR tree-optimization/95906
PR target/70314
* match.pd ((c ? a : b) op d, (c ? a : b) op (c ? d : e),
(v ? w : 0) ? a : b, c1 ? c2 ? a : b : b): New transformations.
(op (c ? a : b
shed it as a branch.
Apart from the obvious (making sure it bootstraps, running the testsuite,
adding a few tests), what missing pieces do you consider a strict
requirement for this to have a chance to reach master one day as an
experimental option?
--
Marc Glissecommit 4adb494e88323bf41ee2c
oesn't matter for this patch.
2020-08-05 Marc Glisse
PR tree-optimization/95906
PR target/70314
* match.pd ((c ? a : b) op d, (c ? a : b) op (c ? d : e),
(v ? w : 0) ? a : b, c1 ? c2 ? a : b : b): New transformations.
(op (c ? a : b)): Update to ma
h directly exits the
function, instead of just giving up on this particular transformation and
trying the next one. I'll reorder my transformations to work around this,
but it looks like a pre-existing limitation.
--
Marc Glisse
On Mon, 3 Aug 2020, Richard Biener wrote:
On Sat, Aug 1, 2020 at 9:29 AM Marc Glisse wrote:
Hello,
this transformation is quite straightforward, without overflow, 3*X==15 is
the same as X==5 and 3*X==5 cannot happen. Adding a single_use restriction
for the first case didn't seem nece
strap+regtest on x86_64-pc-linux-gnu.
2020-08-03 Marc Glisse
PR tree-optimization/95433
* match.pd (X * C1 == C2): New transformation.
* gcc.c-torture/execute/pr23135.c: Add -fwrapv to avoid
undefined behavior.
* gcc.dg/tree-ssa/pr95433.c: New file.
--
, we
can always extend it later...
--
Marc Glisse
eturn non-0 because it swapped the operands,
which should not be sufficient to enable the transformation.
--
Marc Glisse
On Fri, 31 Jul 2020, Marc Glisse wrote:
On Fri, 31 Jul 2020, Richard Sandiford wrote:
Marc Glisse writes:
On Fri, 31 Jul 2020, Richard Sandiford wrote:
Marc Glisse writes:
+/* (c ? a : b) op (c ? d : e) --> c ? (a op d) : (b op e) */
+ (simplify
+ (op (vec_cond:s @0 @1
On Fri, 31 Jul 2020, Richard Sandiford wrote:
Marc Glisse writes:
On Fri, 31 Jul 2020, Richard Sandiford wrote:
Marc Glisse writes:
+/* (c ? a : b) op (c ? d : e) --> c ? (a op d) : (b op e) */
+ (simplify
+ (op (vec_cond:s @0 @1 @2) (vec_cond:s @0 @3 @4))
+ (with
+ {
+ t
On Fri, 31 Jul 2020, Richard Biener wrote:
On Fri, Jul 31, 2020 at 1:39 PM Richard Biener
wrote:
On Fri, Jul 31, 2020 at 1:35 PM Richard Biener
wrote:
On Thu, Jul 30, 2020 at 9:49 AM Marc Glisse wrote:
When vector comparisons were forced to use vec_cond_expr, we lost a number
of
uter
AVX512 SSE-style vec-cond and you then would get a mismatch.
Ah, I thought the SSE-style vec_cond was impossible in AVX512 mode, at
least I couldn't generate one in a few tests, but I didn't try very hard.
So indeed better add a type compatibility check.
Ok, it can't hurt.
--
Marc Glisse
On Fri, 31 Jul 2020, Richard Sandiford wrote:
Marc Glisse writes:
+/* (c ? a : b) op (c ? d : e) --> c ? (a op d) : (b op e) */
+ (simplify
+ (op (vec_cond:s @0 @1 @2) (vec_cond:s @0 @3 @4))
+ (with
+ {
+ tree rhs1, rhs2 = NULL;
+ rhs1 = fold_binary (op, type, @1, @3);
+
:2 and not :1 (is it a hack so true is 1 and not
-1?), but that doesn't matter for this patch.
Regtest+bootstrap on x86_64-pc-linux-gnu
2020-07-30 Marc Glisse
PR tree-optimization/95906
PR target/70314
* match.pd ((c ? a : b) op d, (c ? a : b) op (c ? d : e),
On Thu, 23 Jul 2020, Marc Glisse wrote:
On Wed, 22 Jul 2020, Roger Sayle wrote:
Many thanks for the peer review and feedback. I completely agree that
POPCOUNT
and PARITY iterators simplifies things and handle the IFN_ variants.
Is there a reason why the iterators cannot be used for this
BUILT_IN_POPCOUNTL BUILT_IN_POPCOUNTLL
+ BUILT_IN_POPCOUNTIMAX)
+ parity (BUILT_IN_PARITY BUILT_IN_PARITYL BUILT_IN_PARITYLL
+BUILT_IN_PARITYIMAX)
+ (simplify
+(bit_and (popcount @0) integer_onep)
+(parity @0)))
--
Marc Glisse
t and int64_t, is extending the right thing to do?
Will it eventually simplify to ((int64_t)(i128>>64)|i64)>=0
--
Marc Glisse
could only happen in "#pragma fenv_access off" regions, which
seems to imply that it would be the front-end's responsibility (although
it would need help from the back-end to know the default value to fold
to).
--
Marc Glisse
pass-through on the
arguments and the result.
--
Marc Glisse
b_c_p==true (including the asm, here). Otherwise, any _b_c_p can be
optimized to true, because for a boolean
b is the same as b ? true : false
__builtin_constant_p(b ? true : false) would be the same as b ?
__builtin_constant_p(true) : __builtin_constant_p(false), i.e. true.
It is too bad we don't have any optimization pass using ranges between IPA
and thread1, that would have gotten rid of the comparisons, and hence the
temptation to thread. Adding always_inline on atomic_add (or flatten on
the caller) does help: EVRP removes the comparisons.
Do you see a way forward without changing what thread1 does or declaring
the testcase as unsupported?
--
Marc Glisse
rtain point.
What is this point supposed to be? If I understood you right,
106t.thread1 is already too late - why is it so?
Small remark: shouldn't __atomic_add_const be marked with the
always_inline attribute, since it isn't usable when it isn't inlined?
--
Marc Glisse
he change can be seen as a
simplification and should be pushed to master. It regtests fine.
2020-06-20 Marc Glisse
* include/bits/stl_algo.h (__includes): Simplify the code.
(as with the patch for std::optional, I still haven't worked on my ssh key
issue and cannot currently pus
ne-linux-gnu.
OK for master ?
Cheers,
Przemyslaw
gcc/ChangeLog:
PR tree-optimization/94880
* match.pd (A | B) - B -> (A & ~B): New simplification.
gcc/testsuite/ChangeLog:
PR tree-optimization/94880
* gcc.dg/tree-ssa/pr94880.c: New Test.
--
Marc Glisse
trapped and tested on aarch64-none-linux-gnu.
OK for master ?
Cheers,
Przemyslaw
gcc/ChangeLog:
PR tree-optimization/94880
* match.pd (A | B) - B -> (A & ~B): New simplification.
gcc/testsuite/ChangeLog:
PR tree-optimization/94880
* gcc.dg/tree-ssa/pr94880.c: New Test.
--
Marc Glisse
= 0
Yes you can. It is illegal to use either expression if ptr_a and ptr_b do
not point inside the same object, and objects are not allowed to be larger
than half the address space.
Comparing arbitrary pointers (not in the same object) is done with
(uintptr_t)ptr_a > (uintptr_t)ptr_b.
--
Marc Glisse
Or am I missing some cases?
(I didn't look at the patch and if that's the right condition, just
randomly commenting on this line)
--
Marc Glisse
On Thu, 4 Jun 2020, Richard Biener wrote:
On Thu, Jun 4, 2020 at 11:34 AM Ville Voutilainen via Gcc-patches
wrote:
On Thu, 4 Jun 2020 at 11:53, Marc Glisse wrote:
On Thu, 4 Jun 2020, Ville Voutilainen wrote:
On Thu, 4 Jun 2020 at 11:00, Marc Glisse wrote:
Maybe create a buffer, fill
On Thu, 4 Jun 2020, Ville Voutilainen wrote:
On Thu, 4 Jun 2020 at 11:53, Marc Glisse wrote:
On Thu, 4 Jun 2020, Ville Voutilainen wrote:
On Thu, 4 Jun 2020 at 11:00, Marc Glisse wrote:
Maybe create a buffer, fill it with some non-zero values (-1?), then call
placement new, and read some
On Thu, 4 Jun 2020, Ville Voutilainen wrote:
On Thu, 4 Jun 2020 at 11:00, Marc Glisse wrote:
Maybe create a buffer, fill it with some non-zero values (-1?), then call
placement new, and read some value in the middle of the buffer, possibly
with some protection against optimizations? Ah, no
ly
with some protection against optimizations? Ah, no, actual constructors
are fine, it is only the inlined initialization that happens with the
defaulted constructor that zeroes things.
--
Marc Glisse
years.
What I feared was some regression where it would yield worse code in some
cases, or lose some property (not guaranteed by the standard) like
triviality (to the point of affecting the ABI?), but I couldn't see
anything like that happening.
(we still have PR86173 causing unnecessary
On Thu, 4 Jun 2020, Ville Voutilainen wrote:
On Thu, 4 Jun 2020 at 01:52, Marc Glisse wrote:
Hello,
is there any drawback to the attached patch? It changes the code generated for
I don't get it. The noexceptness of the defaulted default constructor
should be a computation
o
2020-06-04 Marc Glisse
* include/std/optional (optional()): Explicitly define it.
(I don't currently have a setup that would enable me to commit anything. I'll
try to fix it eventually, but likely not so soon)
--
Marc Glissediff --git a/libstdc++-v3/include/std/optional b/li
tr + 255 or ptr - 1?
(pointer_plus ptr 255) would mean ptr - 1 on a platform where the second
argument of pointer_plus has size 1 byte.
Do note that I am not a reviewer, what I say isn't final.
--
Marc Glisse
i integer_zerop) to just @i before reaching this, but it
doesn't make the transformation wrong.
Same remark as above for TYPE_OVERFLOW_UNDEFINED, is that for the sake of
-fsanitize=pointer-overflow?
--
Marc Glisse
c_limits says here is not very meaningful, and users can't rely on
it 100%.
By default, numeric_limits gives yes if IEC support exists on the
platform. The change would sometimes make it say no, when we know for sure
that this support is not enabled at the beginning of the translation unit.
Why not...
--
Marc Glisse
e which regularly adds such flags to
innocent packages).
With (or without) your patch, if a user has the bad -isystem and does
#include , it will never see libstdc++'s version of stdlib.h,
which contains important extra content, so that's still not working
properly.
--
Marc Glisse
On Fri, 10 Apr 2020, Martin Liška wrote:
On 4/9/20 10:13 AM, Jonathan Wakely wrote:
On Thu, 9 Apr 2020 at 09:05, Marc Glisse wrote:
Note that the matching is not 1-to-1. Array vs non-array and
aligned vs non-aligned seem important, but sized and unsized delete can
both match the same new
vs non-aligned seem important, but sized and unsized delete can
both match the same new, IIUC. Not sure about the nothrow versions...
--
Marc Glisse
is feature is getting rather painful, sorry...
--
Marc Glisse
On Mon, 24 Feb 2020, Li Jia He wrote:
Hi,
On 2020/2/22 11:12 PM, Marc Glisse wrote:
On Tue, 18 Feb 2020, Li Jia He wrote:
Also the pattern doing the standalone transform does
/* Optimize TRUNC_MOD_EXPR by a power of two into a BIT_AND_EXPR,
i.e. "X % C" into "X & (
lt;< (i % 54)) will transfer to (0x1234ULL << (i & 54))).
How exactly did you use power_of_two_cand? As shown in the transformation
above, it combines with integer_pow2p, it doesn't replace it.
--
Marc Glisse
red because the output is a single insn) but
not this new one, where it would not be ignored. That's not very
consistent.
--
Marc Glisse
that not
transforming when we don't see the comparison is likely on purpose. Plus,
if @5 was in a signed 1-bit type, it may look more like -1 than 1 and
break the transformation (is that forbidden as return type of a
comparion?).
--
Marc Glisse
use nop_convert for both (instead of
nop_convert1 and 2), but for constants that wouldn't work, so this looks
good.
--
Marc Glisse
tends the 1/2/3 grouping to be able to group like (plus
(nop_convert2? @0) (convert2? @1))
so either both will be present or none (meaning that when grouping you
can choose the "cheaper"
test for one in case you know the conversions will be the same).
Nice.
--
Marc Glisse
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