X-Git-Url: https://git.xonotic.org/?a=blobdiff_plain;f=fold.c;h=e41fd526f1207aa3894d191efc3f58c896aab8de;hb=b654594adbbf4422bfd8ded8e2d133f455e59377;hp=6a8cec232e1e31d5b5d43129cc83e01473bba494;hpb=d0ee56f25f6fe0e62c4490cc436e9ae2466e511d;p=xonotic%2Fgmqcc.git diff --git a/fold.c b/fold.c index 6a8cec2..e41fd52 100644 --- a/fold.c +++ b/fold.c @@ -123,15 +123,6 @@ static GMQCC_INLINE bool vec3_pbool(vec3_t a) { return (a.x && a.y && a.z); } -static GMQCC_INLINE bool fold_can_1(const ast_value *val) { - return (ast_istype(((ast_expression*)(val)), ast_value) && val->hasvalue && (val->cvq == CV_CONST) && - ((ast_expression*)(val))->vtype != TYPE_FUNCTION); -} - -static GMQCC_INLINE bool fold_can_2(const ast_value *v1, const ast_value *v2) { - return fold_can_1(v1) && fold_can_1(v2); -} - static lex_ctx_t fold_ctx(fold_t *fold) { lex_ctx_t ctx; if (fold->parser->lex) @@ -164,6 +155,13 @@ static GMQCC_INLINE bool fold_immediate_true(fold_t *fold, ast_value *v) { return !!v->constval.vfunc; } +/* Handy macros to determine if an ast_value can be constant folded. */ +#define fold_can_1(X) \ + (ast_istype(((ast_expression*)(X)), ast_value) && (X)->hasvalue && ((X)->cvq == CV_CONST) && \ + ((ast_expression*)(X))->vtype != TYPE_FUNCTION) + +#define fold_can_2(X, Y) (fold_can_1(X) && fold_can_1(Y)) + #define fold_immvalue_float(E) ((E)->constval.vfloat) #define fold_immvalue_vector(E) ((E)->constval.vvec) #define fold_immvalue_string(E) ((E)->constval.vstring) @@ -323,7 +321,7 @@ static GMQCC_INLINE ast_expression *fold_op_mul_vec(fold_t *fold, vec3_t vec, as 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) + if (x != -1) return (ast_expression*)ast_binary_new(fold_ctx(fold), INSTR_MUL_F, fold_constgen_float(fold, x), out); } return NULL; @@ -383,13 +381,17 @@ static GMQCC_INLINE ast_expression *fold_op_sub(fold_t *fold, ast_value *a, ast_ static GMQCC_INLINE ast_expression *fold_op_mul(fold_t *fold, ast_value *a, ast_value *b) { if (isfloat(a)) { - if (isfloat(b) && fold_can_2(a, b)) - return fold_constgen_vector(fold, vec3_mulvf(fold_immvalue_vector(b), fold_immvalue_float(a))); - else if (fold_can_2(a, b)) - return fold_constgen_float(fold, fold_immvalue_float(a) * fold_immvalue_float(b)); + if (isvector(b)) { + if (fold_can_2(a, b)) + return fold_constgen_vector(fold, vec3_mulvf(fold_immvalue_vector(b), fold_immvalue_float(a))); + } else { + if (fold_can_2(a, b)) + return fold_constgen_float(fold, fold_immvalue_float(a) * fold_immvalue_float(b)); + } } else if (isvector(a)) { - if (isfloat(b) && fold_can_2(a, b)) { - return fold_constgen_vector(fold, vec3_mulvf(fold_immvalue_vector(a), fold_immvalue_float(b))); + if (isfloat(b)) { + if (fold_can_2(a, b)) + return fold_constgen_vector(fold, vec3_mulvf(fold_immvalue_vector(a), fold_immvalue_float(b))); } else { if (fold_can_2(a, b)) { return fold_constgen_float(fold, vec3_mulvv(fold_immvalue_vector(a), fold_immvalue_vector(b))); @@ -416,8 +418,21 @@ static GMQCC_INLINE ast_expression *fold_op_div(fold_t *fold, ast_value *a, ast_ } else if (isvector(a)) { if (fold_can_2(a, b)) return fold_constgen_vector(fold, vec3_mulvf(fold_immvalue_vector(a), 1.0f / fold_immvalue_float(b))); - else if (fold_can_1(b)) - return fold_constgen_float (fold, 1.0f / fold_immvalue_float(b)); + else { + return (ast_expression*)ast_binary_new( + fold_ctx(fold), + INSTR_MUL_VF, + (ast_expression*)a, + (fold_can_1(b)) + ? (ast_expression*)fold_constgen_float(fold, 1.0f / fold_immvalue_float(b)) + : (ast_expression*)ast_binary_new( + fold_ctx(fold), + INSTR_DIV_F, + (ast_expression*)fold->imm_float[1], + (ast_expression*)b + ) + ); + } } return NULL; } @@ -478,8 +493,8 @@ static GMQCC_INLINE ast_expression *fold_op_andor(fold_t *fold, ast_value *a, as fold, ((or) ? (fold_immediate_true(fold, a) || fold_immediate_true(fold, b)) : (fold_immediate_true(fold, a) && fold_immediate_true(fold, b))) - ? 1.0f - : 0.0f + ? 1 + : 0 ); } } @@ -541,7 +556,7 @@ ast_expression *fold_op(fold_t *fold, const oper_info *info, ast_expression **op case 2: if(!b) return NULL; case 1: if(!a) { - compile_error(fold_ctx(fold), "interal error: fold_op no operands to fold\n"); + compile_error(fold_ctx(fold), "internal error: fold_op no operands to fold\n"); return NULL; } } @@ -568,5 +583,59 @@ ast_expression *fold_op(fold_t *fold, const oper_info *info, ast_expression **op case opid2('=','='): return fold_op_cmp (fold, a, b, false); case opid2('~','P'): return fold_op_bnot (fold, a); } + compile_error(fold_ctx(fold), "internal error: attempted to constant-fold for unsupported operator"); return NULL; } + +/* + * These are all the actual constant folding methods that happen in between + * the AST/IR stage of the compiler , i.e eliminating branches for const + * expressions, which is the only supported thing so far. We undefine the + * testing macros here because an ir_value is differant than an ast_value. + */ +#undef isfloat +#undef isstring +#undef isvector +#undef fold_immvalue_float +#undef fold_immvalue_string +#undef fold_immvalue_vector +#undef fold_can_1 +#undef fold_can_2 + +#define isfloat(X) ((X)->vtype == TYPE_FLOAT) +/*#define isstring(X) ((X)->vtype == TYPE_STRING)*/ +/*#define isvector(X) ((X)->vtype == TYPE_VECTOR)*/ +#define fold_immvalue_float(X) ((X)->constval.vfloat) +/*#define fold_immvalue_vector(X) ((X)->constval.vvec)*/ +/*#define fold_immvalue_string(X) ((X)->constval.vstring)*/ +#define fold_can_1(X) ((X)->hasvalue && (X)->cvq == CV_CONST) +/*#define fold_can_2(X,Y) (fold_can_1(X) && fold_can_1(Y))*/ + + +int fold_cond(ir_value *condval, ast_function *func, ast_ifthen *branch) { + if (isfloat(condval) && fold_can_1(condval) && OPTS_OPTIMIZATION(OPTIM_CONST_FOLD_DCE)) { + ast_expression_codegen *cgen; + ir_block *elide; + ir_value *dummy; + bool istrue = (fold_immvalue_float(condval) == 1.0f && branch->on_true); + bool isfalse = (fold_immvalue_float(condval) == 0.0f && branch->on_false); + ast_expression *path = (istrue) ? branch->on_true : + (isfalse) ? branch->on_false : NULL; + if (!path) + return false; + if (!(elide = ir_function_create_block(ast_ctx(branch), func->ir_func, ast_function_label(func, ((istrue) ? "ontrue" : "onfalse"))))) + return false; + if (!(*(cgen = path->codegen))((ast_expression*)path, func, false, &dummy)) + return false; + if (!ir_block_create_jump(func->curblock, ast_ctx(branch), elide)) + return false; + /* + * now the branch has been eliminated and the correct block for the constant evaluation + * is expanded into the current block for the function. + */ + func->curblock = elide; + ++opts_optimizationcount[OPTIM_CONST_FOLD_DCE]; + return true; + } + return -1; /* nothing done */ +}