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Dale Weiler 2015-01-06 20:39:20 -05:00
parent 2b10d588e4
commit 6fee3ec363
1 changed files with 6 additions and 23 deletions
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29
fold.c
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@ -52,6 +52,7 @@ typedef union {
sfloat_t s;
} sfloat_cast_t;
/* Exception flags */
typedef enum {
SFLOAT_NOEXCEPT = 0,
SFLOAT_INVALID = 1,
@ -61,6 +62,7 @@ typedef enum {
SFLOAT_INEXACT = 32
} sfloat_exceptionflags_t;
/* Rounding modes */
typedef enum {
SFLOAT_ROUND_NEAREST_EVEN,
SFLOAT_ROUND_DOWN,
@ -68,6 +70,7 @@ typedef enum {
SFLOAT_ROUND_TO_ZERO
} sfloat_roundingmode_t;
/* Underflow tininess-detection mode */
typedef enum {
SFLOAT_TAFTER,
SFLOAT_TBEFORE
@ -544,7 +547,7 @@ static GMQCC_INLINE void sfloat_init(sfloat_state_t *state) {
/*
* There is two stages to constant folding in GMQCC: there is the parse
* stage constant folding, where, witht he help of the AST, operator
* stage constant folding, where, with the help of the AST, operator
* usages can be constant folded. Then there is the constant folding
* in the IR for things like eliding if statements, can occur.
*
@ -1097,29 +1100,9 @@ static bool fold_check_inexact_float(fold_t *fold, ast_value *a, ast_value *b) {
}
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];
@ -1497,8 +1480,8 @@ ast_expression *fold_op(fold_t *fold, const oper_info *info, ast_expression **op
}
/*
* Constant folding for compiler intrinsics, simaler approach to operator
* folding, primarly: individual functions for each intrinsics to fold,
* Constant folding for compiler intrinsics, similar approach to operator
* folding, primarily: individual functions for each intrinsics to fold,
* and a generic selection function.
*/
static GMQCC_INLINE ast_expression *fold_intrin_isfinite(fold_t *fold, ast_value *a) {