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go/src/cmd/6a/a.y
Russ Cox fefae6eed1 cmd/6g, cmd/8g: move panicindex calls out of line
The old code generated for a bounds check was
                CMP
                JLT ok
                CALL panicindex
        ok:
                ...

The new code is (once the linker finishes with it):
                CMP
                JGE panic
                ...
        panic:
                CALL panicindex

which moves the calls out of line, putting more useful
code in each cache line.  This matters especially in tight
loops, such as in Fannkuch.  The benefit is more modest
elsewhere, but real.

From test/bench/go1, amd64:

benchmark                old ns/op    new ns/op    delta
BenchmarkBinaryTree17   6096092000   6088808000   -0.12%
BenchmarkFannkuch11     6151404000   4020463000  -34.64%
BenchmarkGobDecode        28990050     28894630   -0.33%
BenchmarkGobEncode        12406310     12136730   -2.17%
BenchmarkGzip               179923       179903   -0.01%
BenchmarkGunzip              11219        11130   -0.79%
BenchmarkJSONEncode       86429350     86515900   +0.10%
BenchmarkJSONDecode      334593800    315728400   -5.64%
BenchmarkRevcomp25M     1219763000   1180767000   -3.20%
BenchmarkTemplate        492947600    483646800   -1.89%

And 386:

benchmark                old ns/op    new ns/op    delta
BenchmarkBinaryTree17   6354902000   6243000000   -1.76%
BenchmarkFannkuch11     8043769000   7326965000   -8.91%
BenchmarkGobDecode        19010800     18941230   -0.37%
BenchmarkGobEncode        14077500     13792460   -2.02%
BenchmarkGzip               194087       193619   -0.24%
BenchmarkGunzip              12495        12457   -0.30%
BenchmarkJSONEncode      125636400    125451400   -0.15%
BenchmarkJSONDecode      696648600    685032800   -1.67%
BenchmarkRevcomp25M     2058088000   2052545000   -0.27%
BenchmarkTemplate        602140000    589876800   -2.04%

To implement this, two new instruction forms:

        JLT target      // same as always
        JLT $0, target  // branch expected not taken
        JLT $1, target  // branch expected taken

The linker could also emit the prediction prefixes, but it
does not: expected taken branches are reversed so that the
expected case is not taken (as in example above), and
the default expectaton for such a jump is not taken
already.

R=golang-dev, gri, r, dave
CC=golang-dev
https://golang.org/cl/6248049
2012-05-29 12:09:27 -04:00

659 lines
9.5 KiB
Plaintext

// Inferno utils/6a/a.y
// http://code.google.com/p/inferno-os/source/browse/utils/6a/a.y
//
// Copyright © 1994-1999 Lucent Technologies Inc. All rights reserved.
// Portions Copyright © 1995-1997 C H Forsyth (forsyth@terzarima.net)
// Portions Copyright © 1997-1999 Vita Nuova Limited
// Portions Copyright © 2000-2007 Vita Nuova Holdings Limited (www.vitanuova.com)
// Portions Copyright © 2004,2006 Bruce Ellis
// Portions Copyright © 2005-2007 C H Forsyth (forsyth@terzarima.net)
// Revisions Copyright © 2000-2007 Lucent Technologies Inc. and others
// Portions Copyright © 2009 The Go Authors. All rights reserved.
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
// THE SOFTWARE.
%{
#include <u.h>
#include <stdio.h> /* if we don't, bison will, and a.h re-#defines getc */
#include <libc.h>
#include "a.h"
%}
%union {
Sym *sym;
vlong lval;
double dval;
char sval[8];
Gen gen;
Gen2 gen2;
}
%left '|'
%left '^'
%left '&'
%left '<' '>'
%left '+' '-'
%left '*' '/' '%'
%token <lval> LTYPE0 LTYPE1 LTYPE2 LTYPE3 LTYPE4
%token <lval> LTYPEC LTYPED LTYPEN LTYPER LTYPET LTYPEG
%token <lval> LTYPES LTYPEM LTYPEI LTYPEXC LTYPEX LTYPERT
%token <lval> LCONST LFP LPC LSB
%token <lval> LBREG LLREG LSREG LFREG LMREG LXREG
%token <dval> LFCONST
%token <sval> LSCONST LSP
%token <sym> LNAME LLAB LVAR
%type <lval> con con2 expr pointer offset
%type <gen> mem imm imm2 reg nam rel rem rim rom omem nmem
%type <gen2> nonnon nonrel nonrem rimnon rimrem remrim spec10 spec11
%type <gen2> spec1 spec2 spec3 spec4 spec5 spec6 spec7 spec8 spec9
%%
prog:
| prog
{
stmtline = lineno;
}
line
line:
LLAB ':'
{
if($1->value != pc)
yyerror("redeclaration of %s", $1->name);
$1->value = pc;
}
line
| LNAME ':'
{
$1->type = LLAB;
$1->value = pc;
}
line
| ';'
| inst ';'
| error ';'
inst:
LNAME '=' expr
{
$1->type = LVAR;
$1->value = $3;
}
| LVAR '=' expr
{
if($1->value != $3)
yyerror("redeclaration of %s", $1->name);
$1->value = $3;
}
| LTYPE0 nonnon { outcode($1, &$2); }
| LTYPE1 nonrem { outcode($1, &$2); }
| LTYPE2 rimnon { outcode($1, &$2); }
| LTYPE3 rimrem { outcode($1, &$2); }
| LTYPE4 remrim { outcode($1, &$2); }
| LTYPER nonrel { outcode($1, &$2); }
| LTYPED spec1 { outcode($1, &$2); }
| LTYPET spec2 { outcode($1, &$2); }
| LTYPEC spec3 { outcode($1, &$2); }
| LTYPEN spec4 { outcode($1, &$2); }
| LTYPES spec5 { outcode($1, &$2); }
| LTYPEM spec6 { outcode($1, &$2); }
| LTYPEI spec7 { outcode($1, &$2); }
| LTYPEXC spec8 { outcode($1, &$2); }
| LTYPEX spec9 { outcode($1, &$2); }
| LTYPERT spec10 { outcode($1, &$2); }
| LTYPEG spec11 { outcode($1, &$2); }
nonnon:
{
$$.from = nullgen;
$$.to = nullgen;
}
| ','
{
$$.from = nullgen;
$$.to = nullgen;
}
rimrem:
rim ',' rem
{
$$.from = $1;
$$.to = $3;
}
remrim:
rem ',' rim
{
$$.from = $1;
$$.to = $3;
}
rimnon:
rim ','
{
$$.from = $1;
$$.to = nullgen;
}
| rim
{
$$.from = $1;
$$.to = nullgen;
}
nonrem:
',' rem
{
$$.from = nullgen;
$$.to = $2;
}
| rem
{
$$.from = nullgen;
$$.to = $1;
}
nonrel:
',' rel
{
$$.from = nullgen;
$$.to = $2;
}
| rel
{
$$.from = nullgen;
$$.to = $1;
}
| imm ',' rel
{
$$.from = $1;
$$.to = $3;
}
spec1: /* DATA */
nam '/' con ',' imm
{
$$.from = $1;
$$.from.scale = $3;
$$.to = $5;
}
spec2: /* TEXT */
mem ',' imm2
{
$$.from = $1;
$$.to = $3;
}
| mem ',' con ',' imm2
{
$$.from = $1;
$$.from.scale = $3;
$$.to = $5;
}
spec3: /* JMP/CALL */
',' rom
{
$$.from = nullgen;
$$.to = $2;
}
| rom
{
$$.from = nullgen;
$$.to = $1;
}
spec4: /* NOP */
nonnon
| nonrem
spec5: /* SHL/SHR */
rim ',' rem
{
$$.from = $1;
$$.to = $3;
}
| rim ',' rem ':' LLREG
{
$$.from = $1;
$$.to = $3;
if($$.from.index != D_NONE)
yyerror("dp shift with lhs index");
$$.from.index = $5;
}
spec6: /* MOVW/MOVL */
rim ',' rem
{
$$.from = $1;
$$.to = $3;
}
| rim ',' rem ':' LSREG
{
$$.from = $1;
$$.to = $3;
if($$.to.index != D_NONE)
yyerror("dp move with lhs index");
$$.to.index = $5;
}
spec7:
rim ','
{
$$.from = $1;
$$.to = nullgen;
}
| rim
{
$$.from = $1;
$$.to = nullgen;
}
| rim ',' rem
{
$$.from = $1;
$$.to = $3;
}
spec8: /* CMPPS/CMPPD */
reg ',' rem ',' con
{
$$.from = $1;
$$.to = $3;
$$.to.offset = $5;
}
spec9: /* shufl */
imm ',' rem ',' reg
{
$$.from = $3;
$$.to = $5;
if($1.type != D_CONST)
yyerror("illegal constant");
$$.to.offset = $1.offset;
}
spec10: /* RET/RETF */
{
$$.from = nullgen;
$$.to = nullgen;
}
| imm
{
$$.from = $1;
$$.to = nullgen;
}
spec11: /* GLOBL */
mem ',' imm
{
$$.from = $1;
$$.to = $3;
}
| mem ',' con ',' imm
{
$$.from = $1;
$$.from.scale = $3;
$$.to = $5;
}
rem:
reg
| mem
rom:
rel
| nmem
| '*' reg
{
$$ = $2;
}
| '*' omem
{
$$ = $2;
}
| reg
| omem
rim:
rem
| imm
rel:
con '(' LPC ')'
{
$$ = nullgen;
$$.type = D_BRANCH;
$$.offset = $1 + pc;
}
| LNAME offset
{
$$ = nullgen;
if(pass == 2)
yyerror("undefined label: %s", $1->name);
$$.type = D_BRANCH;
$$.sym = $1;
$$.offset = $2;
}
| LLAB offset
{
$$ = nullgen;
$$.type = D_BRANCH;
$$.sym = $1;
$$.offset = $1->value + $2;
}
reg:
LBREG
{
$$ = nullgen;
$$.type = $1;
}
| LFREG
{
$$ = nullgen;
$$.type = $1;
}
| LLREG
{
$$ = nullgen;
$$.type = $1;
}
| LMREG
{
$$ = nullgen;
$$.type = $1;
}
| LSP
{
$$ = nullgen;
$$.type = D_SP;
}
| LSREG
{
$$ = nullgen;
$$.type = $1;
}
| LXREG
{
$$ = nullgen;
$$.type = $1;
}
imm2:
'$' con2
{
$$ = nullgen;
$$.type = D_CONST;
$$.offset = $2;
}
imm:
'$' con
{
$$ = nullgen;
$$.type = D_CONST;
$$.offset = $2;
}
| '$' nam
{
$$ = $2;
$$.index = $2.type;
$$.type = D_ADDR;
/*
if($2.type == D_AUTO || $2.type == D_PARAM)
yyerror("constant cannot be automatic: %s",
$2.sym->name);
*/
}
| '$' LSCONST
{
$$ = nullgen;
$$.type = D_SCONST;
memcpy($$.sval, $2, sizeof($$.sval));
}
| '$' LFCONST
{
$$ = nullgen;
$$.type = D_FCONST;
$$.dval = $2;
}
| '$' '(' LFCONST ')'
{
$$ = nullgen;
$$.type = D_FCONST;
$$.dval = $3;
}
| '$' '(' '-' LFCONST ')'
{
$$ = nullgen;
$$.type = D_FCONST;
$$.dval = -$4;
}
| '$' '-' LFCONST
{
$$ = nullgen;
$$.type = D_FCONST;
$$.dval = -$3;
}
mem:
omem
| nmem
omem:
con
{
$$ = nullgen;
$$.type = D_INDIR+D_NONE;
$$.offset = $1;
}
| con '(' LLREG ')'
{
$$ = nullgen;
$$.type = D_INDIR+$3;
$$.offset = $1;
}
| con '(' LSP ')'
{
$$ = nullgen;
$$.type = D_INDIR+D_SP;
$$.offset = $1;
}
| con '(' LSREG ')'
{
$$ = nullgen;
$$.type = D_INDIR+$3;
$$.offset = $1;
}
| con '(' LLREG '*' con ')'
{
$$ = nullgen;
$$.type = D_INDIR+D_NONE;
$$.offset = $1;
$$.index = $3;
$$.scale = $5;
checkscale($$.scale);
}
| con '(' LLREG ')' '(' LLREG '*' con ')'
{
$$ = nullgen;
$$.type = D_INDIR+$3;
$$.offset = $1;
$$.index = $6;
$$.scale = $8;
checkscale($$.scale);
}
| '(' LLREG ')'
{
$$ = nullgen;
$$.type = D_INDIR+$2;
}
| '(' LSP ')'
{
$$ = nullgen;
$$.type = D_INDIR+D_SP;
}
| '(' LLREG '*' con ')'
{
$$ = nullgen;
$$.type = D_INDIR+D_NONE;
$$.index = $2;
$$.scale = $4;
checkscale($$.scale);
}
| '(' LLREG ')' '(' LLREG '*' con ')'
{
$$ = nullgen;
$$.type = D_INDIR+$2;
$$.index = $5;
$$.scale = $7;
checkscale($$.scale);
}
nmem:
nam
{
$$ = $1;
}
| nam '(' LLREG '*' con ')'
{
$$ = $1;
$$.index = $3;
$$.scale = $5;
checkscale($$.scale);
}
nam:
LNAME offset '(' pointer ')'
{
$$ = nullgen;
$$.type = $4;
$$.sym = $1;
$$.offset = $2;
}
| LNAME '<' '>' offset '(' LSB ')'
{
$$ = nullgen;
$$.type = D_STATIC;
$$.sym = $1;
$$.offset = $4;
}
offset:
{
$$ = 0;
}
| '+' con
{
$$ = $2;
}
| '-' con
{
$$ = -$2;
}
pointer:
LSB
| LSP
{
$$ = D_AUTO;
}
| LFP
con:
LCONST
| LVAR
{
$$ = $1->value;
}
| '-' con
{
$$ = -$2;
}
| '+' con
{
$$ = $2;
}
| '~' con
{
$$ = ~$2;
}
| '(' expr ')'
{
$$ = $2;
}
con2:
LCONST
{
$$ = $1 & 0xffffffffLL;
}
| '-' LCONST
{
$$ = -$2 & 0xffffffffLL;
}
| LCONST '-' LCONST
{
$$ = ($1 & 0xffffffffLL) +
(($3 & 0xffffLL) << 32);
}
| '-' LCONST '-' LCONST
{
$$ = (-$2 & 0xffffffffLL) +
(($4 & 0xffffLL) << 32);
}
expr:
con
| expr '+' expr
{
$$ = $1 + $3;
}
| expr '-' expr
{
$$ = $1 - $3;
}
| expr '*' expr
{
$$ = $1 * $3;
}
| expr '/' expr
{
$$ = $1 / $3;
}
| expr '%' expr
{
$$ = $1 % $3;
}
| expr '<' '<' expr
{
$$ = $1 << $4;
}
| expr '>' '>' expr
{
$$ = $1 >> $4;
}
| expr '&' expr
{
$$ = $1 & $3;
}
| expr '^' expr
{
$$ = $1 ^ $3;
}
| expr '|' expr
{
$$ = $1 | $3;
}