From 69252071ba7de94acba4c994ed8c537d03bd937a Mon Sep 17 00:00:00 2001 From: Dale Weiler Date: Sat, 31 Aug 2013 12:57:24 -0400 Subject: [PATCH] Prevent divide by zero for / and % operations in constant folding (previously caused compiler SIGFPE), instead "inf" is generated for both cases. This closes #124 --- fold.c | 45 ++++++++++++++++++++++++++++++++++++++------- 1 file changed, 38 insertions(+), 7 deletions(-) diff --git a/fold.c b/fold.c index 74b9e4f..c977805 100644 --- a/fold.c +++ b/fold.c @@ -201,11 +201,25 @@ static GMQCC_INLINE bool fold_immediate_true(fold_t *fold, ast_value *v) { ((ast_expression*)(X))->vtype != TYPE_FUNCTION) #define fold_can_2(X, Y) (fold_can_1(X) && fold_can_1(Y)) +#define fold_can_div(X) (fold_immvalue_float(X) != 0.0f) #define fold_immvalue_float(E) ((E)->constval.vfloat) #define fold_immvalue_vector(E) ((E)->constval.vvec) #define fold_immvalue_string(E) ((E)->constval.vstring) +#ifdef INFINITY +# define fold_infinity_float INFINITY +#else +# define fold_infinity_float (1.0 / 0.0) +#endif /*! INFINITY */ + +#define fold_infinity_vector \ + vec3_create( \ + fold_infinity_float, \ + fold_infinity_float, \ + fold_infinity_float \ + ) + fold_t *fold_init(parser_t *parser) { fold_t *fold = (fold_t*)mem_a(sizeof(fold_t)); fold->parser = parser; @@ -222,9 +236,11 @@ fold_t *fold_init(parser_t *parser) { (void)fold_constgen_float (fold, 0.0f); (void)fold_constgen_float (fold, 1.0f); (void)fold_constgen_float (fold, -1.0f); + (void)fold_constgen_float (fold, fold_infinity_float); /* +inf */ (void)fold_constgen_vector(fold, vec3_create(0.0f, 0.0f, 0.0f)); (void)fold_constgen_vector(fold, vec3_create(-1.0f, -1.0f, -1.0f)); + (void)fold_constgen_vector(fold, fold_infinity_vector); /* +inf */ return fold; } @@ -454,12 +470,23 @@ static GMQCC_INLINE ast_expression *fold_op_mul(fold_t *fold, ast_value *a, ast_ static GMQCC_INLINE ast_expression *fold_op_div(fold_t *fold, ast_value *a, ast_value *b) { if (isfloat(a)) { - if (fold_can_2(a, b)) - return fold_constgen_float(fold, fold_immvalue_float(a) / fold_immvalue_float(b)); + if (fold_can_2(a, b)) { + if (fold_can_div(b)) + return fold_constgen_float(fold, fold_immvalue_float(a) / fold_immvalue_float(b)); + else + return (ast_expression*)fold->imm_float[3]; /* inf */ + } } 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_2(a, b)) { + if (fold_can_div(b)) { + printf("hit wrong logic\n"); + return fold_constgen_vector(fold, vec3_mulvf(fold_immvalue_vector(a), 1.0f / fold_immvalue_float(b))); + } + else { + printf("hit logic\n"); + return (ast_expression*)fold->imm_vector[2]; /* inf */ + } + } else { return (ast_expression*)ast_binary_new( fold_ctx(fold), INSTR_MUL_VF, @@ -479,8 +506,12 @@ static GMQCC_INLINE ast_expression *fold_op_div(fold_t *fold, ast_value *a, ast_ } static GMQCC_INLINE ast_expression *fold_op_mod(fold_t *fold, ast_value *a, ast_value *b) { - if (fold_can_2(a, b)) - return fold_constgen_float(fold, (qcfloat_t)(((qcint_t)fold_immvalue_float(a)) % ((qcint_t)fold_immvalue_float(b)))); + if (fold_can_2(a, b)) { + if (fold_can_div(b)) + return fold_constgen_float(fold, (qcfloat_t)(((qcint_t)fold_immvalue_float(a)) % ((qcint_t)fold_immvalue_float(b)))); + else + return (ast_expression*)fold->imm_float[3]; /* inf */ + } return NULL; } -- 2.39.2