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author | Richard Sandiford <richard.sandiford@linaro.org> | 2017-08-30 11:19:39 +0000 |
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committer | Richard Sandiford <rsandifo@gcc.gnu.org> | 2017-08-30 11:19:39 +0000 |
commit | db61b7f923b769142156eab047c94b04bb7adaae (patch) | |
tree | 522f1a6eed83a6d3571b7d5746f0fbeb9c488141 /gcc/rtl.h | |
parent | b397965cae46d88d4c274fb2ecdde9a4714a4e6a (diff) | |
download | gcc-db61b7f923b769142156eab047c94b04bb7adaae.zip gcc-db61b7f923b769142156eab047c94b04bb7adaae.tar.gz gcc-db61b7f923b769142156eab047c94b04bb7adaae.tar.bz2 |
[66/77] Use scalar_mode for constant integers
This patch treats the mode associated with an integer constant as a
scalar_mode. We can't use the more natural-sounding scalar_int_mode
because we also use (const_int 0) for bounds-checking modes. (It might
be worth adding a bounds-specific code instead, but that's for another
day.)
This exposes a latent bug in simplify_immed_subreg, which for
vectors of CONST_WIDE_INTs would pass the vector mode rather than
the element mode to rtx_mode_t.
I think the:
/* We can get a 0 for an error mark. */
|| GET_MODE_CLASS (mode) == MODE_VECTOR_INT
|| GET_MODE_CLASS (mode) == MODE_VECTOR_FLOAT
in immed_double_const is dead. trunc_int_mode (via gen_int_mode)
would go on to ICE if the mode fitted in a HWI, and surely plenty
of other code would be confused to see a const_int be interpreted
as a vector. We should instead be using CONST0_RTX (mode) if we
need a safe constant for a particular mode.
We didn't try to make these functions take scalar_mode arguments
because in many cases that would be too invasive at this stage.
Maybe it would become feasible in future. Also, the long-term
direction should probably be to add modes to constant integers
rather than have then as VOIDmode odd-ones-out. That would remove
the need for rtx_mode_t and thus remove the question whether they
should use scalar_int_mode, scalar_mode or machine_mode.
The patch also uses scalar_mode for the CONST_DOUBLE handling
in loc_descriptor. In that case the mode can legitimately be
either floating-point or integral.
2017-08-30 Richard Sandiford <richard.sandiford@linaro.org>
Alan Hayward <alan.hayward@arm.com>
David Sherwood <david.sherwood@arm.com>
gcc/
* emit-rtl.c (immed_double_const): Use is_a <scalar_mode> instead
of separate mode class checks. Do not allow vector modes here.
(immed_wide_int_const): Use as_a <scalar_mode>.
* explow.c (trunc_int_for_mode): Likewise.
* rtl.h (wi::int_traits<rtx_mode_t>::get_precision): Likewise.
(wi::shwi): Likewise.
(wi::min_value): Likewise.
(wi::max_value): Likewise.
* dwarf2out.c (loc_descriptor): Likewise.
* simplify-rtx.c (simplify_immed_subreg): Fix rtx_mode_t argument
for CONST_WIDE_INT.
Co-Authored-By: Alan Hayward <alan.hayward@arm.com>
Co-Authored-By: David Sherwood <david.sherwood@arm.com>
From-SVN: r251517
Diffstat (limited to 'gcc/rtl.h')
-rw-r--r-- | gcc/rtl.h | 9 |
1 files changed, 4 insertions, 5 deletions
@@ -2120,8 +2120,7 @@ namespace wi inline unsigned int wi::int_traits <rtx_mode_t>::get_precision (const rtx_mode_t &x) { - gcc_checking_assert (x.second != BLKmode && x.second != VOIDmode); - return GET_MODE_PRECISION (x.second); + return GET_MODE_PRECISION (as_a <scalar_mode> (x.second)); } inline wi::storage_ref @@ -2166,7 +2165,7 @@ namespace wi inline wi::hwi_with_prec wi::shwi (HOST_WIDE_INT val, machine_mode mode) { - return shwi (val, GET_MODE_PRECISION (mode)); + return shwi (val, GET_MODE_PRECISION (as_a <scalar_mode> (mode))); } /* Produce the smallest number that is represented in MODE. The precision @@ -2174,7 +2173,7 @@ wi::shwi (HOST_WIDE_INT val, machine_mode mode) inline wide_int wi::min_value (machine_mode mode, signop sgn) { - return min_value (GET_MODE_PRECISION (mode), sgn); + return min_value (GET_MODE_PRECISION (as_a <scalar_mode> (mode)), sgn); } /* Produce the largest number that is represented in MODE. The precision @@ -2182,7 +2181,7 @@ wi::min_value (machine_mode mode, signop sgn) inline wide_int wi::max_value (machine_mode mode, signop sgn) { - return max_value (GET_MODE_PRECISION (mode), sgn); + return max_value (GET_MODE_PRECISION (as_a <scalar_mode> (mode)), sgn); } extern void init_rtlanal (void); |