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Added constant folding support for '*' .. Clever ascii trick prevail :D

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This commit is contained in:
Dale Weiler 2013-07-31 10:40:17 +00:00
parent 5e38c800f6
commit 8dd125c8f3
1 changed files with 86 additions and 11 deletions
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91
fold.c
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@ -45,9 +45,12 @@ static GMQCC_INLINE bool fold_possible(const ast_value *val) {
((ast_expression*)val)->vtype != TYPE_FUNCTION; /* why not for functions? */
}
#define isfloat(X) (((ast_expression*)(X))->vtype == TYPE_FLOAT && fold_possible(X))
#define isvector(X) (((ast_expression*)(X))->vtype == TYPE_VECTOR && fold_possible(X))
#define isstring(X) (((ast_expression*)(X))->vtype == TYPE_STRING && fold_possible(X))
#define isfloatonly(X) (((ast_expression*)(X))->vtype == TYPE_FLOAT)
#define isvectoronly(X) (((ast_expression*)(X))->vtype == TYPE_VECTOR)
#define isstringonly(X) (((ast_expression*)(X))->vtype == TYPE_STRING)
#define isfloat(X) (isfloatonly (X) && fold_possible(X))
#define isvector(X) (isvectoronly(X) && fold_possible(X))
#define isstring(X) (isstringonly(X) && fold_possible(X))
#define isfloats(X,Y) (isfloat (X) && isfloat (Y))
#define isvectors(X,Y) (isvector (X) && isvector(Y))
#define isstrings(X,Y) (isstring (X) && isstring(Y))
@ -106,7 +109,6 @@ static GMQCC_INLINE vec3_t vec3_xorvf(vec3_t a, qcfloat_t b) {
return out;
}
#if 0
static GMQCC_INLINE qcfloat_t vec3_mulvv(vec3_t a, vec3_t b) {
return (a.x * b.x + a.y * b.y + a.z * b.z);
}
@ -119,7 +121,6 @@ static GMQCC_INLINE vec3_t vec3_mulvf(vec3_t a, qcfloat_t b) {
out.z = a.z * b;
return out;
}
#endif
static GMQCC_INLINE bool vec3_cmp(vec3_t a, vec3_t b) {
return a.x == b.x &&
@ -280,6 +281,82 @@ ast_expression *fold_constgen_string(fold_t *fold, const char *str, bool transla
return (ast_expression*)out;
}
static GMQCC_INLINE ast_expression *fold_op_mul_vec(fold_t *fold, vec3_t *vec, ast_value *sel, const char *set) {
/*
* vector-component constant folding works by matching the component sets
* to eliminate expensive operations on whole-vectors (3 components at runtime).
* to achive this effect in a clean manner this function generalizes the
* values through the use of a set paramater, which is used as an indexing method
* for creating the elided ast binary expression.
*
* Consider 'n 0 0' where y, and z need to be tested for 0, and x is
* used as the value in a binary operation generating an INSTR_MUL instruction
* to acomplish the indexing of the correct component value we use set[0], set[1], set[2]
* as x, y, z, where the values of those operations return 'x', 'y', 'z'. Because
* of how ASCII works we can easily deliniate:
* vec.z is the same as set[2]-'x' for when set[2] is 'z', 'z'-'x' results in a
* literal value of 2, using this 2, we know that taking the address of vec->x (float)
* and indxing it with this literal will yeild the immediate address of that component
*
* Of course more work needs to be done to generate the correct index for the ast_member_new
* call, which is no problem: set[0]-'x' suffices that job.
*/
qcfloat_t x = (&vec->x)[set[0]-'x'];
qcfloat_t y = (&vec->x)[set[1]-'x'];
qcfloat_t z = (&vec->x)[set[2]-'x'];
if (!y && !z) {
ast_expression *out;
++opts_optimizationcount[OPTIM_VECTOR_COMPONENTS];
out = (ast_expression*)ast_member_new(fold_ctx(fold), (ast_expression*)sel, set[0]-'x', NULL);
out->node.keep = false;
((ast_member*)out)->rvalue = true;
if (!x != -1)
return (ast_expression*)ast_binary_new(fold_ctx(fold), INSTR_MUL_F, fold_constgen_float(fold, x), out);
}
return NULL;
}
static GMQCC_INLINE ast_expression *fold_op_mul(fold_t *fold, ast_value *a, ast_value *b) {
if (isfloatonly(a)) {
return (fold_possible(a) && fold_possible(b))
? fold_constgen_vector(fold, vec3_mulvf(fold_immvalue_vector(b), fold_immvalue_float(a))) /* a=float, b=vector */
: NULL; /* cannot fold them */
} else if (isfloats(a, b)) {
return fold_constgen_float(fold, fold_immvalue_float(a) * fold_immvalue_float(b)); /* a=float, b=float */
} else if (isvectoronly(a)) {
if (isfloat(b) && fold_possible(a))
return fold_constgen_vector(fold, vec3_mulvf(fold_immvalue_vector(a), fold_immvalue_float(b))); /* a=vector, b=float */
else if (isvector(b)) {
/*
* if we made it here the two ast values are both vectors. However because vectors are represented as
* three float values, constant folding can still occur within reason of the individual const-qualification
* of the components the vector is composed of.
*/
if (fold_possible(a) && fold_possible(b))
return fold_constgen_float(fold, vec3_mulvv(fold_immvalue_vector(a), fold_immvalue_vector(b)));
else if (OPTS_OPTIMIZATION(OPTIM_VECTOR_COMPONENTS) && fold_possible(a)) {
vec3_t vec = fold_immvalue_vector(a);
ast_expression *out;
if ((out = fold_op_mul_vec(fold, &vec, b, "xyz"))) return out;
if ((out = fold_op_mul_vec(fold, &vec, b, "yxz"))) return out;
if ((out = fold_op_mul_vec(fold, &vec, b, "zxy"))) return out;
return NULL;
} else if (OPTS_OPTIMIZATION(OPTIM_VECTOR_COMPONENTS) && fold_possible(b)) {
vec3_t vec = fold_immvalue_vector(b);
ast_expression *out;
if ((out = fold_op_mul_vec(fold, &vec, a, "xyz"))) return out;
if ((out = fold_op_mul_vec(fold, &vec, a, "yxz"))) return out;
if ((out = fold_op_mul_vec(fold, &vec, a, "zxy"))) return out;
return NULL;
}
}
}
return NULL;
}
ast_expression *fold_op(fold_t *fold, const oper_info *info, ast_expression **opexprs) {
ast_value *a = (ast_value*)opexprs[0];
ast_value *b = (ast_value*)opexprs[1];
@ -345,9 +422,7 @@ ast_expression *fold_op(fold_t *fold, const oper_info *info, ast_expression **op
return isfloat(a) ? fold_constgen_float (fold, ~(qcint_t)fold_immvalue_float(a))
: NULL;
case opid1('*'):
/* TODO: seperate function for this case */
return NULL;
case opid1('*'): return fold_op_mul(fold, a, b);
case opid1('/'):
/* TODO: seperate function for this case */
return NULL;