https://gcc.gnu.org/g:02c3910f75ddae52dd59775bf9a6c4452bbdd0ac
commit r16-782-g02c3910f75ddae52dd59775bf9a6c4452bbdd0ac
Author: Richard Sandiford <richard.sandif...@arm.com>
Date: Wed May 21 10:01:29 2025 +0100
genemit: Consistently use operand arrays in gen_* functions
One slightly awkward part about emitting the generator function
bodies is that:
* define_insn and define_expand routines have a separate argument for
each operand, named "operand0" upwards.
* define_split and define_peephole2 routines take a pointer to an array,
named "operands".
* the C++ preparation code for expands, splits and peephole2s uses an
array called "operands" to refer to the operands.
* the automatically-generated code uses individual "operand<N>"
variables to refer to the operands.
So define_expands have to store the incoming arguments into an operands
array before the md file's C++ code, then copy the operands array back
to the individual variables before the automatically-generated code.
splits and peephole2s have to copy the incoming operands array to
individual variables after the md file's C++ code, creating more
local variables that are live across calls to rtx_alloc.
This patch tries to simplify things by making the whole function
body use the operands array in preference to individual variables.
define_insns and define_expands store their arguments to the array
on entry.
This would have pros and cons on its own, but having a single array
helps with future efforts to reduce the duplication between gen_*
functions.
gcc/
* genemit.cc (gen_rtx_scratch, gen_exp): Use operands[%d] rather
than
operand%d.
(start_gen_insn): Mark the incoming arguments as const and store
them to an operands array.
(gen_expand, gen_split): Remove copies into and out of the operands
array.
Diff:
---
gcc/genemit.cc | 61 ++++++++++++++++++----------------------------------------
1 file changed, 19 insertions(+), 42 deletions(-)
diff --git a/gcc/genemit.cc b/gcc/genemit.cc
index 90f36e293b4b..ed87f1a903d3 100644
--- a/gcc/genemit.cc
+++ b/gcc/genemit.cc
@@ -71,7 +71,7 @@ gen_rtx_scratch (rtx x, enum rtx_code subroutine_type, FILE
*file)
{
if (subroutine_type == DEFINE_PEEPHOLE2)
{
- fprintf (file, "operand%d", XINT (x, 0));
+ fprintf (file, "operands[%d]", XINT (x, 0));
}
else
{
@@ -108,21 +108,21 @@ gen_exp (rtx x, enum rtx_code subroutine_type, char *used,
{
if (used[XINT (x, 0)])
{
- fprintf (file, "copy_rtx (operand%d)", XINT (x, 0));
+ fprintf (file, "copy_rtx (operands[%d])", XINT (x, 0));
return;
}
used[XINT (x, 0)] = 1;
}
- fprintf (file, "operand%d", XINT (x, 0));
+ fprintf (file, "operands[%d]", XINT (x, 0));
return;
case MATCH_OP_DUP:
fprintf (file, "gen_rtx_fmt_");
for (i = 0; i < XVECLEN (x, 1); i++)
fprintf (file, "e");
- fprintf (file, " (GET_CODE (operand%d), ", XINT (x, 0));
+ fprintf (file, " (GET_CODE (operands[%d]), ", XINT (x, 0));
if (GET_MODE (x) == VOIDmode)
- fprintf (file, "GET_MODE (operand%d)", XINT (x, 0));
+ fprintf (file, "GET_MODE (operands[%d])", XINT (x, 0));
else
fprintf (file, "%smode", GET_MODE_NAME (GET_MODE (x)));
for (i = 0; i < XVECLEN (x, 1); i++)
@@ -137,7 +137,7 @@ gen_exp (rtx x, enum rtx_code subroutine_type, char *used,
fprintf (file, "gen_rtx_fmt_");
for (i = 0; i < XVECLEN (x, 2); i++)
fprintf (file, "e");
- fprintf (file, " (GET_CODE (operand%d)", XINT (x, 0));
+ fprintf (file, " (GET_CODE (operands[%d])", XINT (x, 0));
fprintf (file, ", %smode", GET_MODE_NAME (GET_MODE (x)));
for (i = 0; i < XVECLEN (x, 2); i++)
{
@@ -149,7 +149,7 @@ gen_exp (rtx x, enum rtx_code subroutine_type, char *used,
case MATCH_PARALLEL:
case MATCH_PAR_DUP:
- fprintf (file, "operand%d", XINT (x, 0));
+ fprintf (file, "operands[%d]", XINT (x, 0));
return;
case MATCH_SCRATCH:
@@ -437,14 +437,22 @@ start_gen_insn (FILE *file, const char *name, const
pattern_stats &stats)
fprintf (file, "rtx\ngen_%s (", name);
if (stats.num_generator_args)
for (int i = 0; i < stats.num_generator_args; i++)
- if (i)
- fprintf (file, ",\n\trtx operand%d ATTRIBUTE_UNUSED", i);
- else
- fprintf (file, "rtx operand%d ATTRIBUTE_UNUSED", i);
+ fprintf (file, "%sconst rtx operand%d", i == 0 ? "" : ", ", i);
else
fprintf (file, "void");
fprintf (file, ")\n");
fprintf (file, "{\n");
+ if (stats.num_generator_args)
+ {
+ fprintf (file, " rtx operands[%d] ATTRIBUTE_UNUSED = {",
+ stats.num_operand_vars);
+ for (int i = 0; i < stats.num_generator_args; i++)
+ fprintf (file, "%s operand%d", i == 0 ? "" : ",", i);
+ fprintf (file, " };\n");
+ }
+ else if (stats.num_operand_vars != 0)
+ fprintf (file, " rtx operands[%d] ATTRIBUTE_UNUSED;\n",
+ stats.num_operand_vars);
}
/* Generate the `gen_...' function for a DEFINE_INSN. */
@@ -496,7 +504,6 @@ static void
gen_expand (const md_rtx_info &info, FILE *file)
{
struct pattern_stats stats;
- int i;
char *used;
/* Find out how many operands this function has. */
@@ -523,10 +530,6 @@ gen_expand (const md_rtx_info &info, FILE *file)
return;
}
- /* For each operand referred to only with MATCH_DUPs,
- make a local variable. */
- for (i = stats.num_generator_args; i <= stats.max_dup_opno; i++)
- fprintf (file, " rtx operand%d;\n", i);
fprintf (file, " rtx_insn *_val = 0;\n");
fprintf (file, " start_sequence ();\n");
@@ -539,12 +542,6 @@ gen_expand (const md_rtx_info &info, FILE *file)
if (XSTR (expand, 3) && *XSTR (expand, 3))
{
fprintf (file, " {\n");
- if (stats.num_operand_vars > 0)
- fprintf (file, " rtx operands[%d];\n", stats.num_operand_vars);
-
- /* Output code to copy the arguments into `operands'. */
- for (i = 0; i < stats.num_generator_args; i++)
- fprintf (file, " operands[%d] = operand%d;\n", i, i);
/* Output the special code to be executed before the sequence
is generated. */
@@ -558,16 +555,6 @@ gen_expand (const md_rtx_info &info, FILE *file)
}
emit_c_code (XSTR (expand, 3), can_fail_p, XSTR (expand, 0), file);
- /* Output code to copy the arguments back out of `operands'
- (unless we aren't going to use them at all). */
- if (XVEC (expand, 1) != 0)
- {
- for (i = 0; i <= MAX (stats.max_opno, stats.max_dup_opno); i++)
- {
- fprintf (file, " operand%d = operands[%d];\n", i, i);
- fprintf (file, " (void) operand%d;\n", i);
- }
- }
fprintf (file, " }\n");
}
@@ -606,7 +593,6 @@ static void
gen_split (const md_rtx_info &info, FILE *file)
{
struct pattern_stats stats;
- int i;
rtx split = info.def;
const char *const name =
((GET_CODE (split) == DEFINE_PEEPHOLE2) ? "peephole2" : "split");
@@ -639,8 +625,6 @@ gen_split (const md_rtx_info &info, FILE *file)
fprintf (file, "{\n");
/* Declare all local variables. */
- for (i = 0; i < stats.num_operand_vars; i++)
- fprintf (file, " rtx operand%d;\n", i);
fprintf (file, " rtx_insn *_val = NULL;\n");
if (GET_CODE (split) == DEFINE_PEEPHOLE2)
@@ -663,13 +647,6 @@ gen_split (const md_rtx_info &info, FILE *file)
if (XSTR (split, 3))
emit_c_code (XSTR (split, 3), true, name, file);
- /* Output code to copy the arguments back out of `operands' */
- for (i = 0; i < stats.num_operand_vars; i++)
- {
- fprintf (file, " operand%d = operands[%d];\n", i, i);
- fprintf (file, " (void) operand%d;\n", i);
- }
-
gen_emit_seq (XVEC (split, 2), used, info, file);
/* Call `get_insns' to make a list of all the
