Author: Fraser Cormack Date: 2025-03-05T14:18:51Z New Revision: 760eeac6a22e49a3100c530dd130a7202ae0a56b
URL: https://github.com/llvm/llvm-project/commit/760eeac6a22e49a3100c530dd130a7202ae0a56b DIFF: https://github.com/llvm/llvm-project/commit/760eeac6a22e49a3100c530dd130a7202ae0a56b.diff LOG: [libclc] Reduce bithacking in CLC frexp (#129871) Also replace some magic constants with named ones. Checking against FP zero and using isnan and isinf functions allows the optimizer to create one unified @llvm.is.fpclass intrinsic. This results in fewer more canonical IR instructions. Added: Modified: libclc/clc/lib/generic/math/clc_frexp.cl libclc/clc/lib/generic/math/clc_frexp.inc Removed: ################################################################################ diff --git a/libclc/clc/lib/generic/math/clc_frexp.cl b/libclc/clc/lib/generic/math/clc_frexp.cl index ecc3eb6281b1e..dc9b00f7ef664 100644 --- a/libclc/clc/lib/generic/math/clc_frexp.cl +++ b/libclc/clc/lib/generic/math/clc_frexp.cl @@ -23,6 +23,8 @@ #include <clc/clc_convert.h> #include <clc/internal/clc.h> #include <clc/math/math.h> +#include <clc/relational/clc_isinf.h> +#include <clc/relational/clc_isnan.h> #include <clc/relational/clc_select.h> #include <clc/utils.h> diff --git a/libclc/clc/lib/generic/math/clc_frexp.inc b/libclc/clc/lib/generic/math/clc_frexp.inc index 22966f08579a9..d59ccad9ac98c 100644 --- a/libclc/clc/lib/generic/math/clc_frexp.inc +++ b/libclc/clc/lib/generic/math/clc_frexp.inc @@ -28,17 +28,22 @@ _CLC_OVERLOAD _CLC_DEF __CLC_GENTYPE __clc_frexp(__CLC_GENTYPE x, __CLC_ADDRESS_SPACE __CLC_INTN *ep) { __CLC_INTN i = __CLC_AS_INTN(x); - __CLC_INTN ai = i & 0x7fffffff; - __CLC_INTN d = ai > 0 & ai < 0x00800000; - /* scale subnormal by 2^26 without multiplying */ + __CLC_INTN ai = i & EXSIGNBIT_SP32; + + // Scale subnormal by 2^26 without multiplying + __CLC_INTN is_subnormal = ai > 0 && ai < 0x00800000; __CLC_GENTYPE s = __CLC_AS_GENTYPE(ai | 0x0d800000) - 0x1.0p-100f; - ai = __clc_select(ai, __CLC_AS_INTN(s), d); - __CLC_INTN e = - (ai >> 23) - 126 - __clc_select((__CLC_INTN)0, (__CLC_INTN)26, d); - __CLC_INTN t = ai == (__CLC_INTN)0 | e == (__CLC_INTN)129; - i = (i & (__CLC_INTN)0x80000000) | (__CLC_INTN)0x3f000000 | (ai & 0x007fffff); - *ep = __clc_select(e, (__CLC_INTN)0, t); - return __clc_select(__CLC_AS_GENTYPE(i), x, t); + ai = __clc_select(ai, __CLC_AS_INTN(s), is_subnormal); + __CLC_INTN e = (ai >> EXPSHIFTBITS_SP32) - 126 - + __clc_select((__CLC_INTN)0, (__CLC_INTN)26, is_subnormal); + + i = (i & (__CLC_INTN)SIGNBIT_SP32) | (__CLC_INTN)HALFEXPBITS_SP32 | + (ai & (__CLC_INTN)MANTBITS_SP32); + + __CLC_INTN is_inf_nan_or_zero = + x == __CLC_FP_LIT(0.0) || __clc_isinf(x) || __clc_isnan(x); + *ep = __clc_select(e, (__CLC_INTN)0, is_inf_nan_or_zero); + return __clc_select(__CLC_AS_GENTYPE(i), x, is_inf_nan_or_zero); } #endif @@ -56,19 +61,22 @@ __clc_frexp(__CLC_GENTYPE x, __CLC_ADDRESS_SPACE __CLC_INTN *ep) { _CLC_OVERLOAD _CLC_DEF __CLC_GENTYPE __clc_frexp(__CLC_GENTYPE x, __CLC_ADDRESS_SPACE __CLC_INTN *ep) { __CLC_LONGN i = __CLC_AS_LONGN(x); - __CLC_LONGN ai = i & 0x7fffffffffffffffL; - __CLC_LONGN d = ai > 0 & ai < 0x0010000000000000L; - // scale subnormal by 2^54 without multiplying + __CLC_LONGN ai = i & EXSIGNBIT_DP64; + + // Scale subnormal by 2^54 without multiplying + __CLC_LONGN is_subnormal = ai > 0 && ai < 0x0010000000000000L; __CLC_GENTYPE s = __CLC_AS_GENTYPE(ai | 0x0370000000000000L) - 0x1.0p-968; - ai = __clc_select(ai, __CLC_AS_LONGN(s), d); - __CLC_LONGN e = (ai >> 52) - (__CLC_LONGN)1022 - - __clc_select((__CLC_LONGN)0, (__CLC_LONGN)54, d); - __CLC_LONGN t = ai == 0 | e == 1025; - i = (i & (__CLC_LONGN)0x8000000000000000L) | - (__CLC_LONGN)0x3fe0000000000000L | - (ai & (__CLC_LONGN)0x000fffffffffffffL); - *ep = __CLC_CONVERT_INTN(__clc_select(e, 0L, t)); - return __clc_select(__CLC_AS_GENTYPE(i), x, t); + ai = __clc_select(ai, __CLC_AS_LONGN(s), is_subnormal); + __CLC_LONGN e = (ai >> EXPSHIFTBITS_DP64) - (__CLC_LONGN)1022 - + __clc_select((__CLC_LONGN)0, (__CLC_LONGN)54, is_subnormal); + + i = (i & (__CLC_LONGN)SIGNBIT_DP64) | (__CLC_LONGN)HALFEXPBITS_DP64 | + (ai & (__CLC_LONGN)MANTBITS_DP64); + + __CLC_LONGN is_inf_nan_or_zero = + x == __CLC_FP_LIT(0.0) || __clc_isinf(x) || __clc_isnan(x); + *ep = __CLC_CONVERT_INTN(__clc_select(e, 0L, is_inf_nan_or_zero)); + return __clc_select(__CLC_AS_GENTYPE(i), x, is_inf_nan_or_zero); } #endif _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
