diff options
Diffstat (limited to 'libclc')
| -rw-r--r-- | libclc/generic/include/clc/float/definitions.h | 2 | ||||
| -rw-r--r-- | libclc/generic/lib/math/ilogb.cl | 20 |
2 files changed, 19 insertions, 3 deletions
diff --git a/libclc/generic/include/clc/float/definitions.h b/libclc/generic/include/clc/float/definitions.h index 43335a7..6250123 100644 --- a/libclc/generic/include/clc/float/definitions.h +++ b/libclc/generic/include/clc/float/definitions.h @@ -15,7 +15,7 @@ #define FLT_EPSILON 0x1.0p-23f #define FP_ILOGB0 (-2147483647 - 1) -#define FP_ILOGBNAN (-2147483647 - 1) +#define FP_ILOGBNAN 2147483647 #define M_E_F 0x1.5bf0a8p+1f #define M_LOG2E_F 0x1.715476p+0f diff --git a/libclc/generic/lib/math/ilogb.cl b/libclc/generic/lib/math/ilogb.cl index 7ab7899..050239c 100644 --- a/libclc/generic/lib/math/ilogb.cl +++ b/libclc/generic/lib/math/ilogb.cl @@ -31,7 +31,15 @@ _CLC_OVERLOAD _CLC_DEF int ilogb(float x) { int rs = -118 - (int) clz(ux & MANTBITS_SP32); int r = (int) (ax >> EXPSHIFTBITS_SP32) - EXPBIAS_SP32; r = ax < 0x00800000U ? rs : r; - r = ax > EXPBITS_SP32 | ax == 0 ? 0x80000000 : r; + r = ax == 0 ? FP_ILOGB0 : r; + + // We could merge those 2 tests and have: + // + // r = ax >= EXPBITS_SP32 ? 0x7fffffff : r + // + // since FP_ILOGBNAN is set to INT_MAX, but it's clearer this way and + // FP_ILOGBNAN can change without requiring changes to ilogb() code. + r = ax > EXPBITS_SP32 ? FP_ILOGBNAN : r; r = ax == EXPBITS_SP32 ? 0x7fffffff : r; return r; } @@ -47,7 +55,15 @@ _CLC_OVERLOAD _CLC_DEF int ilogb(double x) { int r = (int) (ax >> EXPSHIFTBITS_DP64) - EXPBIAS_DP64; int rs = -1011 - (int) clz(ax & MANTBITS_DP64); r = ax < 0x0010000000000000UL ? rs : r; - r = ax > 0x7ff0000000000000UL | ax == 0UL ? 0x80000000 : r; + r = ax == 0UL ? FP_ILOGB0 : r; + + // We could merge those 2 tests and have: + // + // r = ax >= 0x7ff0000000000000UL ? 0x7fffffff : r + // + // since FP_ILOGBNAN is set to INT_MAX, but it's clearer this way and + // FP_ILOGBNAN can change without requiring changes to ilogb() code. + r = ax > 0x7ff0000000000000UL ? FP_ILOGBNAN : r; r = ax == 0x7ff0000000000000UL ? 0x7fffffff : r; return r; } |