From: Jan Beulich <jbeulich@suse.com>
To: Binutils <binutils@sourceware.org>
Cc: "H.J. Lu" <hjl.tools@gmail.com>
Subject: [PATCH 1/8] x86: move insn mnemonics to a separate table
Date: Fri, 13 Jan 2023 12:06:32 +0100 [thread overview]
Message-ID: <fa681978-5ee6-16ba-3f08-958f6d1cf805@suse.com> (raw)
In-Reply-To: <beeaf9c6-7d1e-bcc6-624a-918c4a6c293e@suse.com>
Using full pointers to reference the insn mnemonic strings is not very
efficient. With overall string size presently just slightly over 20k,
even a 16-bit value would suffice. Use "unsigned int" for now, as
there's no good use we could presently make of the otherwise saved 16
bits.
For 64-bit builds this reduces table size by 6.25% (prior to the recent
ISA extension additions it would have been 12.5%), with a similar effect
on cache occupation of table entries accessed. For PIE builds of gas
this also reduces the number of base relocations quite a bit (obviously
independent of bitness).
---
An alternative to introducing i386-mnem.h would of course be to put the
#define-s in i386-init.h. That would look like an abuse of the file to
me, but I'd be okay switching to such an approach.
As to further shrinking mnem_off (to 16 bits): I'm intending to drop
i386_opcode_modifier as a separate struct, embedding the fields directly
in insn_template. i386_opcode_modifier presently using only 6 bits from
its 3rd word will allow to shrink insn_template by another word then.
(This would also benefit readabilty of tc-i386*.c, as all the uses of
"opcode_modifier." would go away. This would additionally reduce the
apparent discrepancy between e.g. opcode_modifier.opcode_space and
opcode_modifier.opcode_prefix vs base_opcode and extension_opcode.)
--- a/gas/Makefile.am
+++ b/gas/Makefile.am
@@ -453,7 +453,7 @@ i386_tbl_deps = $(srcdir)/../opcodes/i38
$(srcdir)/../opcodes/i386-reg.tbl \
$(srcdir)/../opcodes/i386-gen.c $(srcdir)/../opcodes/i386-opc.h
-$(srcdir)/../opcodes/i386%init.h $(srcdir)/../opcodes/i386%tbl.h: @MAINT@ $(i386_tbl_deps)
+$(srcdir)/../opcodes/i386%init.h $(srcdir)/../opcodes/i386%tbl.h $(srcdir)/../opcodes/i386%mnem.h: @MAINT@ $(i386_tbl_deps)
@echo '"$@" is outdated wrt "$?"' >&2
@echo 'Please rebuild from the top level or in $(CURDIR)/../opcodes/' >&2
@false
--- a/gas/Makefile.in
+++ b/gas/Makefile.in
@@ -2070,7 +2070,7 @@ development.exp: $(BFDDIR)/development.s
config/tc-i386.o: $(srcdir)/../opcodes/i386-init.h $(srcdir)/../opcodes/i386-tbl.h
-$(srcdir)/../opcodes/i386%init.h $(srcdir)/../opcodes/i386%tbl.h: @MAINT@ $(i386_tbl_deps)
+$(srcdir)/../opcodes/i386%init.h $(srcdir)/../opcodes/i386%tbl.h $(srcdir)/../opcodes/i386%mnem.h: @MAINT@ $(i386_tbl_deps)
@echo '"$@" is outdated wrt "$?"' >&2
@echo 'Please rebuild from the top level or in $(CURDIR)/../opcodes/' >&2
@false
--- a/gas/config/tc-i386.c
+++ b/gas/config/tc-i386.c
@@ -34,6 +34,7 @@
#include "sframe.h"
#include "elf/x86-64.h"
#include "opcodes/i386-init.h"
+#include "opcodes/i386-mnem.h"
#include <limits.h>
#ifndef INFER_ADDR_PREFIX
@@ -2428,7 +2429,7 @@ offset_in_range (offsetT val, int size)
static INLINE const char *insn_name (const insn_template *t)
{
- return t->name;
+ return &i386_mnemonics[t->mnem_off];
}
enum PREFIX_GROUP
--- a/opcodes/Makefile.am
+++ b/opcodes/Makefile.am
@@ -523,7 +523,8 @@ MOSTLYCLEANFILES = aarch64-gen$(EXEEXT_F
z8kgen$(EXEEXT_FOR_BUILD) opc2c$(EXEEXT_FOR_BUILD)
MAINTAINERCLEANFILES = $(srcdir)/aarch64-asm-2.c $(srcdir)/aarch64-dis-2.c \
- $(srcdir)/aarch64-opc-2.c $(srcdir)/i386-tbl.h $(srcdir)/i386-init.h \
+ $(srcdir)/aarch64-opc-2.c \
+ $(srcdir)/i386-tbl.h $(srcdir)/i386-init.h $(srcdir)/i386-mnem.h \
$(srcdir)/ia64-asmtab.c $(srcdir)/z8k-opc.h \
$(srcdir)/msp430-decode.c \
$(srcdir)/rl78-decode.c \
@@ -552,16 +553,17 @@ i386-gen.o: i386-gen.c i386-opc.h $(srcd
config.h sysdep.h
$(COMPILE_FOR_BUILD) -c $(srcdir)/i386-gen.c
-# i386-gen will generate both headers in one go. Use a pattern rule to properly
+# i386-gen will generate all headers in one go. Use a pattern rule to properly
# express this, with the inner dash ('-') arbitrarily chosen to be the stem.
-$(srcdir)/i386%tbl.h $(srcdir)/i386%init.h: @MAINT@ i386-gen$(EXEEXT_FOR_BUILD) i386-opc.tbl i386-reg.tbl i386-opc.h
+$(srcdir)/i386%tbl.h $(srcdir)/i386%init.h $(srcdir)/i386%mnem.h: \
+ @MAINT@ i386-gen$(EXEEXT_FOR_BUILD) i386-opc.tbl i386-reg.tbl i386-opc.h
$(AM_V_GEN)$(CPP) $(DEFS) $(DEFAULT_INCLUDES) $(INCLUDES) $(AM_CPPFLAGS) $(CPPFLAGS) - \
< $(srcdir)/i386-opc.tbl \
| ./i386-gen$(EXEEXT_FOR_BUILD) --srcdir $(srcdir)
-# While not really dependencies, specify i386-{init,tbl}.h here as well to
-# make sure they are re-generated as necessary.
-i386-dis.lo: $(srcdir)/i386-tbl.h $(srcdir)/i386-init.h
+# While not really dependencies, specify other generated i386-*.h here as well
+# to make sure they are re-generated as necessary.
+i386-dis.lo: $(srcdir)/i386-tbl.h $(srcdir)/i386-init.h $(srcdir)/i386-mnem.h
ia64-gen$(EXEEXT_FOR_BUILD): ia64-gen.o $(BUILD_LIB_DEPS)
$(AM_V_CCLD)$(LINK_FOR_BUILD) ia64-gen.o $(BUILD_LIBS)
--- a/opcodes/Makefile.in
+++ b/opcodes/Makefile.in
@@ -758,7 +758,8 @@ MOSTLYCLEANFILES = aarch64-gen$(EXEEXT_F
z8kgen$(EXEEXT_FOR_BUILD) opc2c$(EXEEXT_FOR_BUILD)
MAINTAINERCLEANFILES = $(srcdir)/aarch64-asm-2.c $(srcdir)/aarch64-dis-2.c \
- $(srcdir)/aarch64-opc-2.c $(srcdir)/i386-tbl.h $(srcdir)/i386-init.h \
+ $(srcdir)/aarch64-opc-2.c \
+ $(srcdir)/i386-tbl.h $(srcdir)/i386-init.h $(srcdir)/i386-mnem.h \
$(srcdir)/ia64-asmtab.c $(srcdir)/z8k-opc.h \
$(srcdir)/msp430-decode.c \
$(srcdir)/rl78-decode.c \
@@ -1526,16 +1527,17 @@ i386-gen.o: i386-gen.c i386-opc.h $(srcd
config.h sysdep.h
$(COMPILE_FOR_BUILD) -c $(srcdir)/i386-gen.c
-# i386-gen will generate both headers in one go. Use a pattern rule to properly
+# i386-gen will generate all headers in one go. Use a pattern rule to properly
# express this, with the inner dash ('-') arbitrarily chosen to be the stem.
-$(srcdir)/i386%tbl.h $(srcdir)/i386%init.h: @MAINT@ i386-gen$(EXEEXT_FOR_BUILD) i386-opc.tbl i386-reg.tbl i386-opc.h
+$(srcdir)/i386%tbl.h $(srcdir)/i386%init.h $(srcdir)/i386%mnem.h: \
+ @MAINT@ i386-gen$(EXEEXT_FOR_BUILD) i386-opc.tbl i386-reg.tbl i386-opc.h
$(AM_V_GEN)$(CPP) $(DEFS) $(DEFAULT_INCLUDES) $(INCLUDES) $(AM_CPPFLAGS) $(CPPFLAGS) - \
< $(srcdir)/i386-opc.tbl \
| ./i386-gen$(EXEEXT_FOR_BUILD) --srcdir $(srcdir)
-# While not really dependencies, specify i386-{init,tbl}.h here as well to
-# make sure they are re-generated as necessary.
-i386-dis.lo: $(srcdir)/i386-tbl.h $(srcdir)/i386-init.h
+# While not really dependencies, specify other generated i386-*.h here as well
+# to make sure they are re-generated as necessary.
+i386-dis.lo: $(srcdir)/i386-tbl.h $(srcdir)/i386-init.h $(srcdir)/i386-mnem.h
ia64-gen$(EXEEXT_FOR_BUILD): ia64-gen.o $(BUILD_LIB_DEPS)
$(AM_V_CCLD)$(LINK_FOR_BUILD) ia64-gen.o $(BUILD_LIBS)
--- a/opcodes/i386-gen.c
+++ b/opcodes/i386-gen.c
@@ -1146,12 +1146,26 @@ process_i386_operand_type (FILE *table,
stage, indent);
}
+static char *mkident (const char *mnem)
+{
+ char *ident = xstrdup (mnem), *p = ident;
+
+ do
+ {
+ if (!ISALNUM (*p))
+ *p = '_';
+ }
+ while (*++p);
+
+ return ident;
+}
+
static void
output_i386_opcode (FILE *table, const char *name, char *str,
char *last, int lineno)
{
unsigned int i, length, prefix = 0, space = 0;
- char *base_opcode, *extension_opcode, *end;
+ char *base_opcode, *extension_opcode, *end, *ident;
char *cpu_flags, *opcode_modifier, *operand_types [MAX_OPERANDS];
unsigned long long opcode;
@@ -1245,9 +1259,11 @@ output_i386_opcode (FILE *table, const c
fail (_("%s:%d: %s: residual opcode (0x%0*llx) too large\n"),
filename, lineno, name, 2 * length, opcode);
- fprintf (table, " { \"%s\", 0x%0*llx%s, %lu, %s,\n",
- name, 2 * (int)length, opcode, end, i,
+ ident = mkident (name);
+ fprintf (table, " { MN_%s, 0x%0*llx%s, %lu, %s,\n",
+ ident, 2 * (int)length, opcode, end, i,
extension_opcode ? extension_opcode : "None");
+ free (ident);
process_i386_opcode_modifier (table, opcode_modifier, space, prefix,
operand_types, lineno);
@@ -1565,7 +1581,7 @@ process_i386_opcodes (FILE *table)
{
FILE *fp;
char buf[2048];
- unsigned int i, j, nr;
+ unsigned int i, j, nr, offs;
char *str, *p, *last, *name;
htab_t opcode_hash_table;
struct opcode_hash_entry **opcode_array = NULL;
@@ -1579,6 +1595,7 @@ process_i386_opcodes (FILE *table)
opcode_hash_eq, NULL,
xcalloc, free);
+ fprintf (table, "\n#include \"i386-mnem.h\"\n");
fprintf (table, "\n/* i386 opcode table. */\n\n");
fprintf (table, "static const insn_template i386_optab[] =\n{\n");
@@ -1701,6 +1718,32 @@ process_i386_opcodes (FILE *table)
}
fprintf (table, "};\n");
+
+ /* Emit mnemonics and associated #define-s. */
+ fp = fopen ("i386-mnem.h", "w");
+ if (fp == NULL)
+ fail (_("can't create i386-mnem.h, errno = %s\n"),
+ xstrerror (errno));
+
+ process_copyright (fp);
+
+ fprintf (table, "\n/* i386 mnemonics table. */\n\n");
+ fprintf (table, "const char i386_mnemonics[] =\n");
+ fprintf (fp, "\nextern const char i386_mnemonics[];\n\n");
+
+ for (offs = j = 0; j < i; j++)
+ {
+ name = opcode_array[j]->name;
+ fprintf (table, " \"\\0\"\"%s\"\n", name);
+ str = mkident (name);
+ fprintf (fp, "#define MN_%s %#x\n", str, offs + 1);
+ free (str);
+ offs += strlen (name) + 1;
+ }
+
+ fprintf (table, ";\n");
+
+ fclose (fp);
}
static void
--- a/opcodes/i386-opc.h
+++ b/opcodes/i386-opc.h
@@ -918,7 +918,7 @@ typedef union i386_operand_type
typedef struct insn_template
{
/* instruction name sans width suffix ("mov" for movl insns) */
- const char *name;
+ unsigned int mnem_off;
/* Bitfield arrangement is such that individual fields can be easily
extracted (in native builds at least) - either by at most a masking
next prev parent reply other threads:[~2023-01-13 11:06 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-01-13 11:04 [PATCH 0/8] x86: mnemonic and register string literals Jan Beulich
2023-01-13 11:05 ` [PATCH 1/8] x86: abstract out obtaining of a template's mnemonic Jan Beulich
2023-01-13 11:06 ` Jan Beulich [this message]
2023-01-13 11:12 ` [PATCH 1/8] x86: move insn mnemonics to a separate table Jan Beulich
2023-01-13 11:07 ` [PATCH 3/8] x86: re-use insn mnemonic strings as much as possible Jan Beulich
2023-01-13 11:07 ` [PATCH 4/8] x86: absorb allocation in i386-gen Jan Beulich
2023-01-13 11:08 ` [PATCH 5/8] x86: avoid strcmp() in a few places Jan Beulich
2023-01-13 11:10 ` [PATCH 6/8] x86: embed register names in reg_entry Jan Beulich
2023-01-13 11:11 ` [PATCH 7/8] x86: embed register and alike names in disassembler Jan Beulich
2023-01-13 11:11 ` [PATCH 8/8] x86: split i386-gen's opcode hash entry struct Jan Beulich
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