From dfd047ce6a693a2bc32a8778b06bd08c3d39aa0b Mon Sep 17 00:00:00 2001 From: Jesse Rosenstock Date: Fri, 13 Nov 2020 09:01:26 +0100 Subject: [PATCH] g_typeadjust: Use CF_CHAR for char args If lhs and rhs are either both signed char or both unsigned char, return flags for that type instead of (unsigned) int. The flags are used only for codegen. Currently, this does nothing, since codegen treats chars as ints unless CF_FORCECHAR is set, but it allows more efficient char x char -> int codegen to be added in the future. --- src/cc65/codegen.c | 23 +++++++++++++---------- 1 file changed, 13 insertions(+), 10 deletions(-) diff --git a/src/cc65/codegen.c b/src/cc65/codegen.c index f56abcd95..a58484cf1 100644 --- a/src/cc65/codegen.c +++ b/src/cc65/codegen.c @@ -1433,17 +1433,20 @@ unsigned g_typeadjust (unsigned lhs, unsigned rhs) /* Note that this logic is largely duplicated by ArithmeticConvert. */ - /* Before we apply the integral promotions, we check if both types are unsigned char. - ** If so, we return unsigned int, rather than int, which would be returned by the standard - ** rules. This is only a performance optimization and does not affect correctness, as - ** the flags are only used for code generation, and not to determine types of other - ** expressions containing this one. All unsigned char bit-patterns are valid as both int - ** and unsigned int and represent the same value, so either signed or unsigned int operations - ** can be used. This special case part is not duplicated by ArithmeticConvert. + /* Before we apply the integral promotions, we check if both types are the same character type. + ** If so, we return that type, rather than int, which would be returned by the standard + ** rules. This is only a performance optimization allowing the use of unsigned and/or char + ** operations; it does not affect correctness, as the flags are only used for code generation, + ** and not to determine types of other expressions containing this one. For codgen, CF_CHAR + ** means the operands are char and the result is int (unless CF_FORCECHAR is also set, in + ** which case the result is char). This special case part is not duplicated by + ** ArithmeticConvert. */ - if ((lhs & CF_TYPEMASK) == CF_CHAR && (lhs & CF_UNSIGNED) && - (rhs & CF_TYPEMASK) == CF_CHAR && (rhs & CF_UNSIGNED)) { - return const_flag | CF_UNSIGNED | CF_INT; + if ((lhs & CF_TYPEMASK) == CF_CHAR && (rhs & CF_TYPEMASK) == CF_CHAR && + (lhs & CF_UNSIGNED) == (rhs & CF_UNSIGNED)) { + /* Signedness flags are the same, so just use one of them. */ + const unsigned unsigned_flag = lhs & CF_UNSIGNED; + return const_flag | unsigned_flag | CF_CHAR; } /* Apply integral promotions for types char/short. */