From: Dale Weiler Date: Wed, 31 Jul 2013 10:40:17 +0000 (+0000) Subject: Added constant folding support for '*' .. Clever ascii trick prevail :D X-Git-Tag: v0.3.0~52 X-Git-Url: https://git.rm.cloudns.org/?a=commitdiff_plain;h=8dd125c8f3d79cb6a3e70719ffc5fb3be5905f91;p=xonotic%2Fgmqcc.git Added constant folding support for '*' .. Clever ascii trick prevail :D --- diff --git a/fold.c b/fold.c index 1319f24..c7abaeb 100644 --- a/fold.c +++ b/fold.c @@ -45,12 +45,15 @@ 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 isfloats(X,Y) (isfloat (X) && isfloat(Y)) -#define isvectors(X,Y) (isvector(X) && isvector(Y)) -#define isstrings(X,Y) (isstring(X) && isstring(Y)) +#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)) /* * Implementation of basic vector math for vec3_t, for trivial constant @@ -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;