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[qfcc] Improve handling of negative GA expressions 

Sum expressions pull the negation through extend expressions allowing
them to switch to subtraction when appropriate, and offset_cast reaches
past negation to check for extend expressions. This has eliminated all
negation-only instructions from the motor-point, shaving off more
instructions (now 27 not including the return).
This commit is contained in:
Bill Currie 2023-09-19 00:47:29 +09:00
parent ca01ab2a27
commit 1e274b385d
1 changed files with 22 additions and 1 deletions
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23
tools/qfcc/source/expr_algebra.c
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@ -177,6 +177,12 @@ offset_cast (type_t *type, expr_t *expr, int offset)
return 0; return 0;
} }
} }
if (is_neg (expr)) {
auto e = expr->e.expr.e1;
if (e->type == ex_extend) {
return neg_expr (offset_cast (type, e, offset));
}
}
offset *= type_size (base_type (get_type (expr))); offset *= type_size (base_type (get_type (expr)));
return alias_expr (type, expr, offset); return alias_expr (type, expr, offset);
} }
@ -356,6 +362,13 @@ ext_compat (const expr_t *a, const expr_t *b)
&& a->e.extend.type == b->e.extend.type); && a->e.extend.type == b->e.extend.type);
} }
static expr_t *
extract_extended_neg (const expr_t *expr)
{
auto e = expr->e.extend;
return neg_expr (ext_expr (neg_expr (e.src), e.type, e.extend, e.reverse));
}
static expr_t * static expr_t *
sum_expr (type_t *type, expr_t *a, expr_t *b) sum_expr (type_t *type, expr_t *a, expr_t *b)
{ {
@ -372,6 +385,8 @@ sum_expr (type_t *type, expr_t *a, expr_t *b)
if (a->type == ex_extend) { if (a->type == ex_extend) {
if (b->type == ex_extend) { if (b->type == ex_extend) {
if (ext_compat (a, b)) { if (ext_compat (a, b)) {
// push the sum below the two extends making for a single
// extend of a sum instead of a sum of two extends
auto ext = a->e.extend; auto ext = a->e.extend;
a = a->e.extend.src; a = a->e.extend.src;
b = b->e.extend.src; b = b->e.extend.src;
@ -403,6 +418,12 @@ sum_expr (type_t *type, expr_t *a, expr_t *b)
} }
} }
} }
if (a->type == ex_extend && is_neg (a->e.extend.src)) {
a = extract_extended_neg (a);
}
if (b->type == ex_extend && is_neg (b->e.extend.src)) {
b = extract_extended_neg (b);
}
bool neg = false; bool neg = false;
if ((is_neg (a) && (is_neg (b) || anti_com (b))) if ((is_neg (a) && (is_neg (b) || anti_com (b)))
|| (anti_com (a) && is_neg (b))) { || (anti_com (a) && is_neg (b))) {
@ -1687,7 +1708,7 @@ pga2_yw_wx_xy_geom_yw_wx_xy (expr_t **c, expr_t *a, expr_t *b, algebra_t *alg)
auto geom_type = algebra_mvec_type (alg, 0x04); auto geom_type = algebra_mvec_type (alg, 0x04);
auto sa = offset_cast (stype, a, 2); auto sa = offset_cast (stype, a, 2);
auto sb = offset_cast (stype, b, 2); auto sb = offset_cast (stype, b, 2);
auto cv = alias_expr (ctype, cross_expr (vtype, b, a), 0); auto cv = offset_cast (ctype, cross_expr (vtype, b, a), 0);
c[2] = ext_expr (cv, geom_type, 0, false); c[2] = ext_expr (cv, geom_type, 0, false);
c[3] = neg_expr (scale_expr (algebra_mvec_type (alg, 0x08), sa, sb)); c[3] = neg_expr (scale_expr (algebra_mvec_type (alg, 0x08), sa, sb));