diff options
Diffstat (limited to 'src/commonlib')
| -rw-r--r-- | src/commonlib/include/commonlib/compiler.h | 15 | ||||
| -rw-r--r-- | src/commonlib/include/commonlib/helpers.h | 77 |
2 files changed, 72 insertions, 20 deletions
diff --git a/src/commonlib/include/commonlib/compiler.h b/src/commonlib/include/commonlib/compiler.h index 2e0c454fc9..5078759360 100644 --- a/src/commonlib/include/commonlib/compiler.h +++ b/src/commonlib/include/commonlib/compiler.h @@ -48,4 +48,19 @@ #define __always_inline inline __attribute__((always_inline)) #endif +/* This evaluates to the type of the first expression, unless that is constant + in which case it evalutates to the type of the second. This is useful when + assigning macro parameters to temporary variables, because that would + normally circumvent the special loosened type promotion rules for integer + literals. By using this macro, the promotion can happen at the time the + literal is assigned to the temporary variable. If the literal doesn't fit in + the chosen type, -Werror=overflow will catch it, so this should be safe. */ +#define __TYPEOF_UNLESS_CONST(expr, fallback_expr) __typeof__( \ + __builtin_choose_expr(__builtin_constant_p(expr), fallback_expr, expr)) + +/* This creates a unique local variable name for use in macros. */ +#define __TMPNAME_3(i) __tmpname_##i +#define __TMPNAME_2(i) __TMPNAME_3(i) +#define __TMPNAME __TMPNAME_2(__COUNTER__) + #endif diff --git a/src/commonlib/include/commonlib/helpers.h b/src/commonlib/include/commonlib/helpers.h index adc43ca98b..4429ea41c3 100644 --- a/src/commonlib/include/commonlib/helpers.h +++ b/src/commonlib/include/commonlib/helpers.h @@ -16,6 +16,7 @@ /* This file is for helpers for both coreboot firmware and its utilities. */ #ifndef __ASSEMBLER__ +#include <commonlib/compiler.h> #include <stddef.h> #endif @@ -29,35 +30,71 @@ #define ALIGN_DOWN(x, a) ((x) & ~((__typeof__(x))(a)-1UL)) #define IS_ALIGNED(x, a) (((x) & ((__typeof__(x))(a)-1UL)) == 0) +/* Double-evaluation unsafe min/max, for bitfields and outside of functions */ +#define __CMP_UNSAFE(a, b, op) ((a) op (b) ? (a) : (b)) +#define MIN_UNSAFE(a, b) __CMP_UNSAFE(a, b, <) +#define MAX_UNSAFE(a, b) __CMP_UNSAFE(a, b, >) + +#define __CMP_SAFE(a, b, op, var_a, var_b) ({ \ + __TYPEOF_UNLESS_CONST(a, b) var_a = (a); \ + __TYPEOF_UNLESS_CONST(b, a) var_b = (b); \ + var_a op var_b ? var_a : var_b; \ +}) + +#ifdef __ROMCC__ /* romcc doesn't support __builtin_choose_expr() */ +#define __CMP(a, b, op) __CMP_UNSAFE(a, b, op) +#else +#define __CMP(a, b, op) __builtin_choose_expr( \ + __builtin_constant_p(a) && __builtin_constant_p(b), \ + __CMP_UNSAFE(a, b, op), __CMP_SAFE(a, b, op, __TMPNAME, __TMPNAME)) +#endif + #ifndef MIN -#define MIN(a, b) ((a) < (b) ? (a) : (b)) +#define MIN(a, b) __CMP(a, b, <) #endif #ifndef MAX -#define MAX(a, b) ((a) > (b) ? (a) : (b)) +#define MAX(a, b) __CMP(a, b, >) #endif -#define ABS(a) (((a) < 0) ? (-(a)) : (a)) -#define IS_POWER_OF_2(x) (((x) & ((x) - 1)) == 0) -#define DIV_ROUND_UP(x, y) (((x) + (y) - 1) / (y)) -#define SWAP(a, b) do { \ - typeof(a) tmp = a; \ - a = (typeof(a)) b; \ - b = (typeof(b)) tmp; \ - } while (0) + +#ifndef ABS +#define ABS(a) ({ \ + __typeof__(a) _abs_local_a = (a); \ + (_abs_local_a < 0) ? (-_abs_local_a) : _abs_local_a; \ +}) +#endif + +#define IS_POWER_OF_2(x) ({ \ + __typeof__(x) _power_local_x = (x); \ + (_power_local_x & (_power_local_x - 1)) == 0; \ +}) + +#define DIV_ROUND_UP(x, y) ({ \ + __typeof__(x) _div_local_x = (x); \ + __typeof__(y) _div_local_y = (y); \ + (_div_local_x + _div_local_y - 1) / _div_local_y; \ +}) + +#define SWAP(a, b) do { \ + __typeof__(&(a)) _swap_local_a = &(a); \ + __typeof__(&(b)) _swap_local_b = &(b); \ + __typeof__(a) _swap_local_tmp = *_swap_local_a; \ + *_swap_local_a = *_swap_local_b; \ + *_swap_local_b = _swap_local_tmp; \ +} while (0) + /* * Divide positive or negative dividend by positive divisor and round * to closest integer. Result is undefined for negative divisors and * for negative dividends if the divisor variable type is unsigned. */ -#define DIV_ROUND_CLOSEST(x, divisor)( \ -{ \ - typeof(x) __x = x; \ - typeof(divisor) __d = divisor; \ - (((typeof(x))-1) > 0 || \ - ((typeof(divisor))-1) > 0 || (__x) > 0) ? \ - (((__x) + ((__d) / 2)) / (__d)) : \ - (((__x) - ((__d) / 2)) / (__d)); \ -} \ -) +#define DIV_ROUND_CLOSEST(x, divisor)({ \ + __typeof__(x) _div_local_x = (x); \ + __typeof__(divisor) _div_local_d = (divisor); \ + (((__typeof__(x))-1) > 0 || \ + ((__typeof__(divisor))-1) > 0 || (_div_local_x) > 0) ? \ + ((_div_local_x + (_div_local_d / 2)) / _div_local_d) : \ + ((_div_local_x - (_div_local_d / 2)) / _div_local_d); \ +}) /* Standard units. */ #define KiB (1<<10) |