fold-const.c
282 KB
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fold-const.c (negate_mathfn_p): New function to determine whether a built-in… · 05d362b8
fold-const.c (negate_mathfn_p): New function to determine whether a built-in mathematical function is sign... * fold-const.c (negate_mathfn_p): New function to determine whether a built-in mathematical function is sign preserving, f(-x) == -f(x). Add support for BUILT_IN_ASIN, BUILT_IN_ASINF and BUILT_IN_ASINL. (tree_swap_operands_p): Change API to take an additional argument indicating that the swapped operands evaluate in reverse order. Canonicalize VAR_DECLs and PARM_DECLs last if we can, i.e. neither operand side-effects or we don't care about flag_evaluation_order. (reorder_operands_p): New function to check whether its safe to evaluate the given operands in reverse order. (negate_expr_p): We can always negate integer constants unless we honor -ftrapv and the signed type would overflow. Only allow -(A-B) into B-A if reorder_operands_p says that its OK. Allow negation of COMPLEX_CST if both real and imaginary parts can be negated. Allow negation through floating point extensions and sign-preserving built-in functions. (negate_expr): Move the code to negate integers from "fold" to here. Always negate integer constants unless we honor -ftrapv and the signed type would overflow. Always negate real constants unless we honor -ftrapping-math. Only convert -(A-B) into B-A if allowed by reorder_operands_p. Add support for COMPLEX_CST. Optimize negation through floating point extensions and sign-preserving built-in functions (as defined by negate_mathfn_p). (fold): Adjust calls to tree_swap_operands_p. (fold <NEGATE_EXPR>): Move the remaining negation optimizations to negate_expr_p/negate_expr. (fold <MINUS_EXPR>): Use reorder_operands_p to check whether we're allowed to convert (-A) - B into (-B) - A. From-SVN: r72381
Roger Sayle committed