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Remove the jumpabsolute member from mstatement_s.
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This reduces the struct from 20 to 16 bytes, and thus may save some
RAM. It also may improve CPU cache behavior by keeping more QC code in
L1 and L2 cache, and possibly also improve instruction processing inside
the CPU as all statements are aligned the same way.

On `srv04`, this speeds up Xonotic's `serverbench` from 58.92s real,
57.72s user to 57.72s real, 56.59s user (median of 25).
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@divVerent
divVerent committed Oct 7, 2024
1 parent 0c17657 commit 59e7840
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Showing 4 changed files with 16 additions and 17 deletions.
3 changes: 1 addition & 2 deletions pr_comp.h
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Original file line number Diff line number Diff line change
Expand Up @@ -409,8 +409,7 @@ mfunction_t;
typedef struct mstatement_s
{
opcode_t op;
int operand[3]; // always a global or -1 for unused
int jumpabsolute; // only used by IF, IFNOT, GOTO
int operand[3]; // always a global, or a relative statement offset ([0] for GOTO, [1] for IF/IFNOT), or -1 for unused
}
mstatement_t;

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11 changes: 2 additions & 9 deletions prvm_edict.c
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Original file line number Diff line number Diff line change
Expand Up @@ -2294,19 +2294,17 @@ void PRVM_Prog_Load(prvm_prog_t *prog, const char *filename, unsigned char *data
prog->error_cmd("%s: out of bounds IF/IFNOT (statement %d) in %s", __func__, i, prog->name);
prog->statements[i].op = op;
prog->statements[i].operand[0] = remapglobal(a);
prog->statements[i].operand[1] = -1;
prog->statements[i].operand[1] = b;
prog->statements[i].operand[2] = -1;
prog->statements[i].jumpabsolute = i + b;
break;
case OP_GOTO:
a = (short)a;
if (a + i < 0 || a + i >= prog->progs_numstatements)
prog->error_cmd("%s: out of bounds GOTO (statement %d) in %s", __func__, i, prog->name);
prog->statements[i].op = op;
prog->statements[i].operand[0] = -1;
prog->statements[i].operand[0] = a;
prog->statements[i].operand[1] = -1;
prog->statements[i].operand[2] = -1;
prog->statements[i].jumpabsolute = i + a;
break;
default:
Con_DPrintf("%s: unknown opcode %d at statement %d in %s\n", __func__, (int)op, i, prog->name);
Expand All @@ -2316,7 +2314,6 @@ void PRVM_Prog_Load(prvm_prog_t *prog, const char *filename, unsigned char *data
prog->statements[i].operand[0] = 0;
prog->statements[i].operand[1] =
prog->statements[i].operand[2] = op;
prog->statements[i].jumpabsolute = -1;
break;
case OP_STORE_I:
case OP_ADD_I:
Expand Down Expand Up @@ -2427,7 +2424,6 @@ void PRVM_Prog_Load(prvm_prog_t *prog, const char *filename, unsigned char *data
prog->statements[i].operand[0] = remapglobal(a);
prog->statements[i].operand[1] = remapglobal(b);
prog->statements[i].operand[2] = remapglobal(c);
prog->statements[i].jumpabsolute = -1;
break;
// global none global
case OP_NOT_F:
Expand All @@ -2441,7 +2437,6 @@ void PRVM_Prog_Load(prvm_prog_t *prog, const char *filename, unsigned char *data
prog->statements[i].operand[0] = remapglobal(a);
prog->statements[i].operand[1] = -1;
prog->statements[i].operand[2] = remapglobal(c);
prog->statements[i].jumpabsolute = -1;
break;
// 2 globals
case OP_STOREP_F:
Expand All @@ -2466,7 +2461,6 @@ void PRVM_Prog_Load(prvm_prog_t *prog, const char *filename, unsigned char *data
prog->statements[i].operand[0] = remapglobal(a);
prog->statements[i].operand[1] = remapglobal(b);
prog->statements[i].operand[2] = -1;
prog->statements[i].jumpabsolute = -1;
break;
// 1 global
case OP_CALL0:
Expand All @@ -2493,7 +2487,6 @@ void PRVM_Prog_Load(prvm_prog_t *prog, const char *filename, unsigned char *data
prog->statements[i].operand[0] = remapglobal(a);
prog->statements[i].operand[1] = -1;
prog->statements[i].operand[2] = -1;
prog->statements[i].jumpabsolute = -1;
break;
}
}
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13 changes: 10 additions & 3 deletions prvm_exec.c
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Original file line number Diff line number Diff line change
Expand Up @@ -332,10 +332,17 @@ static void PRVM_PrintStatement(prvm_prog_t *prog, mstatement_t *s)
for ( ; i<10 ; i++)
Con_Print(" ");

if (s->operand[0] >= 0) Con_Printf( "%s", PRVM_GlobalString(prog, s->operand[0], valuebuf, sizeof(valuebuf)));
if (s->operand[1] >= 0) Con_Printf(", %s", PRVM_GlobalString(prog, s->operand[1], valuebuf, sizeof(valuebuf)));
if (s->op == OP_GOTO) {
Con_Printf("statement %i", (int)(s - prog->statements) + s->operand[0]);
} else {
if (s->operand[0] >= 0) Con_Printf( "%s", PRVM_GlobalString(prog, s->operand[0], valuebuf, sizeof(valuebuf)));
}
if (s->op == OP_IF || s->op == OP_IFNOT) {
Con_Printf(", statement %i", (int)(s - prog->statements) + s->operand[1]);
} else {
if (s->operand[1] >= 0) Con_Printf(", %s", PRVM_GlobalString(prog, s->operand[1], valuebuf, sizeof(valuebuf)));
}
if (s->operand[2] >= 0) Con_Printf(", %s", PRVM_GlobalString(prog, s->operand[2], valuebuf, sizeof(valuebuf)));
if (s->jumpabsolute >= 0) Con_Printf(", statement %i", s->jumpabsolute);
Con_Print("\n");
}

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6 changes: 3 additions & 3 deletions prvm_execprogram.h
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Original file line number Diff line number Diff line change
Expand Up @@ -637,7 +637,7 @@ int i;
// and entity, string, field values can never have that value
{
ADVANCE_PROFILE_BEFORE_JUMP();
st = cached_statements + st->jumpabsolute - 1; // offset the st++
st += st->operand[1] - 1; // offset the st++
startst = st;
// no bounds check needed, it is done when loading progs
if (++jumpcount == 10000000 && prvm_runawaycheck)
Expand All @@ -657,7 +657,7 @@ int i;
// and entity, string, field values can never have that value
{
ADVANCE_PROFILE_BEFORE_JUMP();
st = cached_statements + st->jumpabsolute - 1; // offset the st++
st += st->operand[1] - 1; // offset the st++
startst = st;
// no bounds check needed, it is done when loading progs
if (++jumpcount == 10000000 && prvm_runawaycheck)
Expand All @@ -671,7 +671,7 @@ int i;

HANDLE_OPCODE(OP_GOTO):
ADVANCE_PROFILE_BEFORE_JUMP();
st = cached_statements + st->jumpabsolute - 1; // offset the st++
st += st->operand[0] - 1; // offset the st++
startst = st;
// no bounds check needed, it is done when loading progs
if (++jumpcount == 10000000 && prvm_runawaycheck)
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