Author: Matt Arsenault Date: 2026-03-25T13:51:15+01:00 New Revision: d642f598ba421d3d3de791f4854a1131154c3e16
URL: https://github.com/llvm/llvm-project/commit/d642f598ba421d3d3de791f4854a1131154c3e16 DIFF: https://github.com/llvm/llvm-project/commit/d642f598ba421d3d3de791f4854a1131154c3e16.diff LOG: libclc: Update acospi (#188455) This was originally ported from rocm device libs in 084124a8fab6fd71d49ac4928d17c3ef8b350ead. Merge in more recent changes. Added: Modified: libclc/clc/lib/generic/math/clc_acospi.cl libclc/clc/lib/generic/math/clc_acospi.inc Removed: ################################################################################ diff --git a/libclc/clc/lib/generic/math/clc_acospi.cl b/libclc/clc/lib/generic/math/clc_acospi.cl index b8100bbfd04b5..90ebb140d5ce1 100644 --- a/libclc/clc/lib/generic/math/clc_acospi.cl +++ b/libclc/clc/lib/generic/math/clc_acospi.cl @@ -6,13 +6,12 @@ // //===----------------------------------------------------------------------===// -#include "clc/clc_convert.h" -#include "clc/float/definitions.h" #include "clc/internal/clc.h" +#include "clc/math/clc_ep.h" #include "clc/math/clc_fabs.h" #include "clc/math/clc_fma.h" #include "clc/math/clc_mad.h" -#include "clc/math/clc_sqrt.h" +#include "clc/math/clc_sqrt_fast.h" #include "clc/math/math.h" #define __CLC_BODY "clc_acospi.inc" diff --git a/libclc/clc/lib/generic/math/clc_acospi.inc b/libclc/clc/lib/generic/math/clc_acospi.inc index 82d8188ca719d..60902f151adfc 100644 --- a/libclc/clc/lib/generic/math/clc_acospi.inc +++ b/libclc/clc/lib/generic/math/clc_acospi.inc @@ -26,131 +26,114 @@ #if __CLC_FPSIZE == 32 -_CLC_OVERLOAD _CLC_DEF __CLC_GENTYPE __clc_acospi(__CLC_GENTYPE x) { - // Some constants and split constants. - const __CLC_GENTYPE pi = __CLC_FP_LIT(3.1415926535897933e+00); - // 0x3ff921fb54442d18 - const __CLC_GENTYPE piby2_head = __CLC_FP_LIT(1.5707963267948965580e+00); - // 0x3c91a62633145c07 - const __CLC_GENTYPE piby2_tail = __CLC_FP_LIT(6.12323399573676603587e-17); - - __CLC_UINTN ux = __CLC_AS_UINTN(x); - __CLC_UINTN aux = ux & ~SIGNBIT_SP32; - __CLC_INTN xneg = ux != aux; - __CLC_INTN xexp = __CLC_AS_INTN(aux >> EXPSHIFTBITS_SP32) - EXPBIAS_SP32; - - __CLC_GENTYPE y = __CLC_AS_GENTYPE(aux); - - // transform if |x| >= 0.5 - __CLC_INTN transform = xexp >= -1; - - __CLC_GENTYPE y2 = y * y; - __CLC_GENTYPE yt = 0.5f * (1.0f - y); - __CLC_GENTYPE r = transform ? yt : y2; - - // Use a rational approximation for [0.0, 0.5] - __CLC_GENTYPE a = - __clc_mad(r, +_CLC_DEF _CLC_OVERLOAD _CLC_CONST __CLC_FLOATN __clc_acospi(__CLC_FLOATN x) { + const __CLC_FLOATN piinv = 0x1.45f306p-2f; + + __CLC_FLOATN ax = __clc_fabs(x); + + __CLC_FLOATN rt = __clc_mad(-0.5f, ax, 0.5f); + __CLC_FLOATN x2 = ax * ax; + __CLC_FLOATN r = ax > 0.5f ? rt : x2; + + __CLC_FLOATN u = r * __clc_mad(r, __clc_mad(r, __clc_mad(r, __clc_mad(r, __clc_mad(r, - __clc_mad(r, -0.00396137437848476485201154797087F, - -0.0133819288943925804214011424456F), - -0.0565298683201845211985026327361F), - 0.184161606965100694821398249421F); - __CLC_GENTYPE b = __clc_mad(r, -0.836411276854206731913362287293F, - 1.10496961524520294485512696706F); - __CLC_GENTYPE u = r * MATH_DIVIDE(a, b); - - __CLC_GENTYPE s = __clc_sqrt(r); - y = s; - __CLC_GENTYPE s1 = __CLC_AS_GENTYPE(__CLC_AS_UINTN(s) & 0xffff0000); - __CLC_GENTYPE c = MATH_DIVIDE(r - s1 * s1, s + s1); - __CLC_GENTYPE rettn = - 1.0f - MATH_DIVIDE(2.0f * (s + __clc_mad(y, u, -piby2_tail)), pi); - __CLC_GENTYPE rettp = MATH_DIVIDE(2.0f * (s1 + __clc_mad(y, u, c)), pi); - __CLC_GENTYPE rett = xneg ? rettn : rettp; - __CLC_GENTYPE ret = - MATH_DIVIDE(piby2_head - (x - __clc_mad(x, -u, piby2_tail)), pi); - - ret = transform ? rett : ret; - ret = aux > 0x3f800000U ? __CLC_GENTYPE_NAN : ret; - ret = ux == 0x3f800000U ? 0.0f : ret; - ret = ux == 0xbf800000U ? 1.0f : ret; - ret = xexp < -26 ? 0.5f : ret; - return ret; + -0x1.3f1c6cp-8f, 0x1.2ac560p-6f), 0x1.80aab4p-8f), 0x1.e53378p-7f), + 0x1.86680ap-6f), 0x1.b29c5ap-5f); + + __CLC_FLOATN s = __clc_sqrt_fast(r); + __CLC_FLOATN ztp = 2.0f * __clc_mad(s, u, piinv * s); + __CLC_FLOATN ztn = 1.0f - ztp; + __CLC_FLOATN zt = x < 0.0f ? ztn : ztp; + __CLC_FLOATN z = 0.5f - __clc_mad(x, u, piinv * x); + return ax > 0.5f ? zt : z; } #elif __CLC_FPSIZE == 64 -_CLC_OVERLOAD _CLC_DEF __CLC_GENTYPE __clc_acospi(__CLC_GENTYPE x) { - const __CLC_GENTYPE pi = __CLC_FP_LIT(0x1.921fb54442d18p+1); - // 0x3c91a62633145c07 - const __CLC_GENTYPE piby2_tail = __CLC_FP_LIT(6.12323399573676603587e-17); - - __CLC_GENTYPE y = __clc_fabs(x); - __CLC_LONGN xneg = x < __CLC_FP_LIT(0.0); - __CLC_INTN xexp = __CLC_CONVERT_INTN( - (__CLC_AS_ULONGN(y) >> EXPSHIFTBITS_DP64) - EXPBIAS_DP64); - - // abs(x) >= 0.5 - __CLC_LONGN transform = __CLC_CONVERT_LONGN(xexp >= -1); - - // Transform y into the range [0,0.5) - __CLC_GENTYPE r1 = 0.5 * (1.0 - y); - __CLC_GENTYPE s = __clc_sqrt(r1); - __CLC_GENTYPE r = y * y; - r = transform ? r1 : r; - y = transform ? s : y; - - // Use a rational approximation for [0.0, 0.5] - __CLC_GENTYPE un = __clc_fma( - r, - __clc_fma( - r, - __clc_fma(r, - __clc_fma(r, - __clc_fma(r, 0.0000482901920344786991880522822991, - 0.00109242697235074662306043804220), - -0.0549989809235685841612020091328), - 0.275558175256937652532686256258), - -0.445017216867635649900123110649), - 0.227485835556935010735943483075); - - __CLC_GENTYPE ud = __clc_fma( - r, - __clc_fma(r, - __clc_fma(r, - __clc_fma(r, 0.105869422087204370341222318533, - -0.943639137032492685763471240072), - 2.76568859157270989520376345954), - -3.28431505720958658909889444194), - 1.36491501334161032038194214209); - - __CLC_GENTYPE u = r * MATH_DIVIDE(un, ud); - - // Reconstruct acos carefully in transformed region - __CLC_GENTYPE res1 = - __clc_fma(-2.0, MATH_DIVIDE(s + __clc_fma(y, u, -piby2_tail), pi), 1.0); - __CLC_GENTYPE s1 = - __CLC_AS_GENTYPE(__CLC_AS_ULONGN(s) & 0xffffffff00000000UL); - __CLC_GENTYPE c = MATH_DIVIDE(__clc_fma(-s1, s1, r), s + s1); - __CLC_GENTYPE res2 = - MATH_DIVIDE(__clc_fma(2.0, s1, __clc_fma(2.0, c, 2.0 * y * u)), pi); - res1 = xneg ? res1 : res2; - res2 = 0.5 - __clc_fma(x, u, x) / pi; - res1 = transform ? res1 : res2; - - res2 = x == 1.0 ? 0.0 : __CLC_GENTYPE_NAN; - res2 = x == -1.0 ? 1.0 : res2; - res1 = __CLC_CONVERT_LONGN(xexp >= 0) ? res2 : res1; - res1 = __CLC_CONVERT_LONGN(xexp < -56) ? 0.5 : res1; - - return res1; +#define piinv 0x1.45f306dc9c883p-2 + +static _CLC_OVERLOAD _CLC_CONST __CLC_DOUBLEN __clc_acospi_identity( + __CLC_DOUBLEN x, __CLC_DOUBLEN r, __CLC_DOUBLEN u, __CLC_DOUBLEN z) { + __CLC_EP_PAIR s = __clc_ep_ldexp(__clc_ep_sqrt(r), 1); + __CLC_DOUBLEN zm = 1.0 - __clc_mad(s.hi, u, piinv * s.hi); + __CLC_EP_PAIR zp = + __clc_ep_fast_add(__clc_ep_mul(piinv, s), __clc_ep_mul(s, u)); + z = x < 0.0 ? zm : zp.hi; + z = x == -1.0 ? 1.0 : z; + return x == 1.0 ? 0.0 : z; } +_CLC_DEF _CLC_OVERLOAD _CLC_CONST __CLC_DOUBLEN __clc_acospi(__CLC_DOUBLEN x) { + // Computes arccos(x). + // The argument is first reduced by noting that arccos(x) + // is invalid for abs(x) > 1. For denormal and small + // arguments arccos(x) = pi/2 to machine accuracy. + // Remaining argument ranges are handled as follows. + // For abs(x) <= 0.5 use + // arccos(x) = pi/2 - arcsin(x) + // = pi/2 - (x + x^3*R(x^2)) + // where R(x^2) is a rational minimax approximation to + // (arcsin(x) - x)/x^3. + // For abs(x) > 0.5 exploit the identity: + // arccos(x) = pi - 2*arcsin(sqrt(1-x)/2) + // together with the above rational approximation, and + // reconstruct the terms carefully. + + __CLC_DOUBLEN y = __clc_fabs(x); + __CLC_LONGN transform = y >= 0.5; + + __CLC_DOUBLEN rt = __clc_mad(y, -0.5, 0.5); + __CLC_DOUBLEN y2 = y * y; + __CLC_DOUBLEN r = transform ? rt : y2; + + __CLC_DOUBLEN u = r * __clc_mad(r, __clc_mad(r, __clc_mad(r, __clc_mad(r, + __clc_mad(r, __clc_mad(r, __clc_mad(r, __clc_mad(r, + __clc_mad(r, __clc_mad(r, __clc_mad(r, + 0x1.547a51d41fb0bp-7, -0x1.6a3fb0718a8f7p-8), 0x1.a7b91f7177ee8p-8), 0x1.035d3435b8ad8p-9), + 0x1.ff0549b4e0449p-9), 0x1.21604ae288f96p-8), 0x1.6a2b36f9aec49p-8), 0x1.d2b076c914f04p-8), + 0x1.3ce53861f8f1fp-7), 0x1.d1a4529a30a69p-7), 0x1.8723a1d61d2e9p-6), 0x1.b2995e7b7af0fp-5); + + __CLC_DOUBLEN z = 0.5 - __clc_mad(x, u, piinv * x); + + return transform ? __clc_acospi_identity(x, r, u, z) : z; +} + +#undef piinv + #elif __CLC_FPSIZE == 16 -_CLC_OVERLOAD _CLC_DEF __CLC_GENTYPE __clc_acospi(__CLC_GENTYPE x) { - return __CLC_CONVERT_GENTYPE(__clc_acospi(__CLC_CONVERT_FLOATN(x))); +_CLC_DEF _CLC_OVERLOAD _CLC_CONST __CLC_HALFN __clc_acospi(__CLC_HALFN x) { + // Computes arccos(x). + // The argument is first reduced by noting that arccos(x) + // is invalid for abs(x) > 1 and arccos(-x) = arccos(x). + // For denormal and small arguments arccos(x) = pi/2 to machine + // accuracy. Remaining argument ranges are handled as follows. + // For abs(x) <= 0.5 use + // arccos(x) = pi/2 - arcsin(x) + // = pi/2 - (x + x^3*R(x^2)) + // where R(x^2) is a rational minimax approximation to + // (arcsin(x) - x)/x^3. + // For abs(x) > 0.5 exploit the identity: + // arccos(x) = pi - 2*arcsin(sqrt(1-x)/2) + // together with the above rational approximation, and + // reconstruct the terms carefully. + + const __CLC_HALFN piinv = 0x1.46p-2h; + + __CLC_HALFN ax = __clc_fabs(x); + + __CLC_HALFN rt = __clc_mad(-0.5h, ax, 0.5h); + __CLC_HALFN x2 = ax * ax; + __CLC_HALFN r = ax > 0.5h ? rt : x2; + + __CLC_HALFN u = r * __clc_mad(r, 0x1.0b8p-5h, 0x1.a7cp-5h); + + __CLC_HALFN s = __clc_sqrt_fast(r); + __CLC_HALFN ztp = 2.0h * __clc_mad(s, u, piinv * s); + __CLC_HALFN ztn = 1.0h - ztp; + __CLC_HALFN zt = x < 0.0h ? ztn : ztp; + __CLC_HALFN z = 0.5h - __clc_mad(x, u, piinv * x); + return ax > 0.5h ? zt : z; } #endif _______________________________________________ cfe-commits mailing list [email protected] https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
