https://gcc.gnu.org/g:ef32bd8c866a1b8a97f627fad44a42f29757c816
commit r16-195-gef32bd8c866a1b8a97f627fad44a42f29757c816
Author: Richard Sandiford <richard.sandif...@arm.com>
Date: Mon Apr 28 14:40:09 2025 +0100
simplify-rtx: Split out native_decode_int
native_decode_rtx handles integer modes by building up a wide_int
and then converting it to an rtx. This patch splits out the
wide_int part, so that callers who don't want an rtx can avoid
creating garbage rtl.
gcc/
* rtl.h (native_decode_int): Declare.
* simplify-rtx.cc (native_decode_int): New function, split out
from...
(native_decode_rtx): ...here.
Diff:
---
gcc/rtl.h | 2 ++
gcc/simplify-rtx.cc | 38 +++++++++++++++++++++++++-------------
2 files changed, 27 insertions(+), 13 deletions(-)
diff --git a/gcc/rtl.h b/gcc/rtl.h
index 3b676c468805..cc25aed1f494 100644
--- a/gcc/rtl.h
+++ b/gcc/rtl.h
@@ -2443,6 +2443,8 @@ extern void get_full_rtx_cost (rtx, machine_mode, enum
rtx_code, int,
struct full_rtx_costs *);
extern bool native_encode_rtx (machine_mode, rtx, vec<target_unit> &,
unsigned int, unsigned int);
+extern wide_int native_decode_int (const vec<target_unit> &, unsigned int,
+ unsigned int, unsigned int);
extern rtx native_decode_rtx (machine_mode, const vec<target_unit> &,
unsigned int);
extern rtx native_decode_vector_rtx (machine_mode, const vec<target_unit> &,
diff --git a/gcc/simplify-rtx.cc b/gcc/simplify-rtx.cc
index 06b52ca80037..d9aa0493a186 100644
--- a/gcc/simplify-rtx.cc
+++ b/gcc/simplify-rtx.cc
@@ -7713,6 +7713,28 @@ native_decode_vector_rtx (machine_mode mode, const
vec<target_unit> &bytes,
return builder.build ();
}
+/* Extract a PRECISION-bit integer from bytes [FIRST_BYTE, FIRST_BYTE + SIZE)
+ of target memory image BYTES. */
+
+wide_int
+native_decode_int (const vec<target_unit> &bytes, unsigned int first_byte,
+ unsigned int size, unsigned int precision)
+{
+ /* Pull the bytes msb first, so that we can use simple
+ shift-and-insert wide_int operations. */
+ wide_int result (wi::zero (precision));
+ for (unsigned int i = 0; i < size; ++i)
+ {
+ unsigned int lsb = (size - i - 1) * BITS_PER_UNIT;
+ /* Always constant because the inputs are. */
+ unsigned int subbyte
+ = subreg_size_offset_from_lsb (1, size, lsb).to_constant ();
+ result <<= BITS_PER_UNIT;
+ result |= bytes[first_byte + subbyte];
+ }
+ return result;
+}
+
/* Read an rtx of mode MODE from the target memory image given by BYTES,
starting at byte FIRST_BYTE. Each element of BYTES contains BITS_PER_UNIT
bits and the bytes are in target memory order. The image has enough
@@ -7738,19 +7760,9 @@ native_decode_rtx (machine_mode mode, const
vec<target_unit> &bytes,
if (is_a <scalar_int_mode> (mode, &imode)
&& GET_MODE_PRECISION (imode) <= MAX_BITSIZE_MODE_ANY_INT)
{
- /* Pull the bytes msb first, so that we can use simple
- shift-and-insert wide_int operations. */
- unsigned int size = GET_MODE_SIZE (imode);
- wide_int result (wi::zero (GET_MODE_PRECISION (imode)));
- for (unsigned int i = 0; i < size; ++i)
- {
- unsigned int lsb = (size - i - 1) * BITS_PER_UNIT;
- /* Always constant because the inputs are. */
- unsigned int subbyte
- = subreg_size_offset_from_lsb (1, size, lsb).to_constant ();
- result <<= BITS_PER_UNIT;
- result |= bytes[first_byte + subbyte];
- }
+ auto result = native_decode_int (bytes, first_byte,
+ GET_MODE_SIZE (imode),
+ GET_MODE_PRECISION (imode));
return immed_wide_int_const (result, imode);
}
