Committed attached patch.
On 02/03/2023 10:13, Richard Sandiford wrote:
"Andre Vieira (lists)" <andre.simoesdiasvie...@arm.com> writes:
Hey both,
Sorry about that, don't know how I missed those. Just running a test on
that now and will commit when it's done. I assume the comment and 0 ->
byte change can be seen as obvious, especially since it was supposed to
be in my original patch...
Thanks. And yeah, agree it counts as obvious.
Richard
On 27/02/2023 15:46, Richard Sandiford wrote:
Uros Bizjak <ubiz...@gmail.com> writes:
On Fri, Feb 17, 2023 at 8:38 AM Richard Biener <rguent...@suse.de> wrote:
On Thu, 16 Feb 2023, Uros Bizjak wrote:
simplify_subreg can return VOIDmode const_int operand and will
cause ICE in simplify_gen_subreg when this operand is passed to it.
The patch prevents VOIDmode temporary from entering simplify_gen_subreg.
We can't process const_int operand any further, since outermode
is not an integer mode here.
But if it's a CONST_INT then we know it's of int_outermode, no? That is,
doesn't simplify_subreg (mode, ...) always return something in 'mode'
and thus we can always pass just 'mode' as third argument to the
following simplify_gen_subreg call?
You are right. I am testing the attached patch that works too.
Thanks for this, it's the correct fix. But as noted in
https://gcc.gnu.org/pipermail/gcc-patches/2023-January/610920.html,
the final 0 is also wrong for big-endian. Andre?
Richard
Uros.
diff --git a/gcc/simplify-rtx.cc b/gcc/simplify-rtx.cc
index 0a1dd88b0a8..3955929bb70 100644
--- a/gcc/simplify-rtx.cc
+++ b/gcc/simplify-rtx.cc
@@ -7665,7 +7665,7 @@ simplify_context::simplify_subreg (machine_mode
outermode, rtx op,
{
rtx tem = simplify_subreg (int_outermode, op, innermode, byte);
if (tem)
- return simplify_gen_subreg (outermode, tem, GET_MODE (tem), 0);
+ return simplify_gen_subreg (outermode, tem, int_outermode, 0);
}
/* If OP is a vector comparison and the subreg is not changing the
diff --git a/gcc/simplify-rtx.cc b/gcc/simplify-rtx.cc
index
2c82256af664bf2bc43172fc8fb4dfb2849e64b1..3b33afa24617f3185872ddc43284e4c9cd073510
100644
--- a/gcc/simplify-rtx.cc
+++ b/gcc/simplify-rtx.cc
@@ -7667,10 +7667,10 @@ simplify_context::simplify_subreg (machine_mode
outermode, rtx op,
}
}
- /* Try simplifying a SUBREG expression of a non-integer OUTERMODE by using a
- NEW_OUTERMODE of the same size instead, other simplifications rely on
- integer to integer subregs and we'd potentially miss out on optimizations
- otherwise. */
+ /* If the outer mode is not integral, try taking a subreg with the equivalent
+ integer outer mode and then bitcasting the result.
+ Other simplifications rely on integer to integer subregs and we'd
+ potentially miss out on optimizations otherwise. */
if (known_gt (GET_MODE_SIZE (innermode),
GET_MODE_SIZE (outermode))
&& SCALAR_INT_MODE_P (innermode)
@@ -7680,7 +7680,7 @@ simplify_context::simplify_subreg (machine_mode
outermode, rtx op,
{
rtx tem = simplify_subreg (int_outermode, op, innermode, byte);
if (tem)
- return simplify_gen_subreg (outermode, tem, int_outermode, 0);
+ return simplify_gen_subreg (outermode, tem, int_outermode, byte);
}
/* If OP is a vector comparison and the subreg is not changing the
