Author: Matt Arsenault Date: 2026-03-24T08:11:24+01:00 New Revision: ff68154480eccdfeaa18d87fd6d83906e93a85c1
URL: https://github.com/llvm/llvm-project/commit/ff68154480eccdfeaa18d87fd6d83906e93a85c1 DIFF: https://github.com/llvm/llvm-project/commit/ff68154480eccdfeaa18d87fd6d83906e93a85c1.diff LOG: libclc: Update asin (#188094) This was originally ported from rocm device libs in 64a8e1b83e14836f97dab4d28dae498e897804e6. Update for more recent changes. Added: Modified: libclc/clc/lib/generic/math/clc_asin.cl libclc/clc/lib/generic/math/clc_asin.inc Removed: ################################################################################ diff --git a/libclc/clc/lib/generic/math/clc_asin.cl b/libclc/clc/lib/generic/math/clc_asin.cl index 4abe4b6bcf109..bd3208428559e 100644 --- a/libclc/clc/lib/generic/math/clc_asin.cl +++ b/libclc/clc/lib/generic/math/clc_asin.cl @@ -9,10 +9,13 @@ #include "clc/clc_convert.h" #include "clc/float/definitions.h" #include "clc/internal/clc.h" +#include "clc/math/clc_copysign.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_asin.inc" diff --git a/libclc/clc/lib/generic/math/clc_asin.inc b/libclc/clc/lib/generic/math/clc_asin.inc index a1718b81b4bc4..15dc36d015482 100644 --- a/libclc/clc/lib/generic/math/clc_asin.inc +++ b/libclc/clc/lib/generic/math/clc_asin.inc @@ -26,129 +26,137 @@ #if __CLC_FPSIZE == 32 -_CLC_OVERLOAD _CLC_DEF __CLC_GENTYPE __clc_asin(__CLC_GENTYPE x) { - // 0x33a22168 - const __CLC_GENTYPE piby2_tail = __CLC_FP_LIT(7.5497894159e-08); - // 0x3f490fda - const __CLC_GENTYPE hpiby2_head = __CLC_FP_LIT(7.8539812565e-01); - // 0x3fc90fdb - const __CLC_GENTYPE piby2 = __CLC_FP_LIT(1.5707963705e+00); - - __CLC_UINTN ux = __CLC_AS_UINTN(x); - __CLC_UINTN aux = ux & EXSIGNBIT_SP32; - __CLC_UINTN xs = ux ^ aux; - __CLC_GENTYPE spiby2 = __CLC_AS_GENTYPE(xs | __CLC_AS_UINTN(piby2)); - __CLC_INTN xexp = __CLC_AS_INTN(aux >> EXPSHIFTBITS_SP32) - EXPBIAS_SP32; - __CLC_GENTYPE y = __CLC_AS_GENTYPE(aux); - - // abs(x) >= 0.5 - __CLC_INTN transform = xexp >= -1; - - __CLC_GENTYPE y2 = y * y; - __CLC_GENTYPE rt = __CLC_FP_LIT(0.5) * (__CLC_FP_LIT(1.0) - y); - __CLC_GENTYPE r = transform ? rt : y2; - - // Use a rational approximation for [0.0, 0.5] - __CLC_GENTYPE a = - __clc_mad(r, +_CLC_DEF _CLC_OVERLOAD _CLC_CONST __CLC_GENTYPE __clc_asin(__CLC_GENTYPE x) { + // Computes arcsin(x). + // The argument is first reduced by noting that arcsin(x) + // is invalid for abs(x) > 1 and arcsin(-x) = -arcsin(x). + // For denormal and small arguments arcsin(x) = x to machine + // accuracy. Remaining argument ranges are handled as follows. + // For abs(x) <= 0.5 use + // arcsin(x) = x + x^3*R(x^2) + // where R(x^2) is a polynomial minimax approximation to + // (arcsin(x) - x)/x^3. + // For abs(x) > 0.5 exploit the identity: + // arcsin(x) = pi/2 - 2*arcsin(sqrt(1-x)/2) + // together with the above polynomial approximation, and + // reconstruct the terms carefully. + + __CLC_GENTYPE ax = __clc_fabs(x); + __CLC_GENTYPE tx = __clc_mad(ax, -0.5f, 0.5f); + __CLC_GENTYPE x2 = x * x; + __CLC_GENTYPE r = ax >= 0.5f ? tx : x2; + + __CLC_GENTYPE 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); - __CLC_GENTYPE s1 = __CLC_AS_GENTYPE(__CLC_AS_UINTN(s) & 0xffff0000); - __CLC_GENTYPE c = MATH_DIVIDE(__clc_mad(-s1, s1, r), s + s1); - __CLC_GENTYPE p = __clc_mad(2.0f * s, u, -__clc_mad(c, -2.0f, piby2_tail)); - __CLC_GENTYPE q = __clc_mad(s1, -2.0f, hpiby2_head); - __CLC_GENTYPE vt = hpiby2_head - (p - q); - __CLC_GENTYPE v = __clc_mad(y, u, y); - v = transform ? vt : v; + 0x1.38434ep-5f, 0x1.bf8bb4p-7f), 0x1.069878p-5f), 0x1.6c8362p-5f), + 0x1.33379p-4f), 0x1.555558p-3f); - __CLC_GENTYPE ret = __CLC_AS_GENTYPE(xs | __CLC_AS_UINTN(v)); - ret = aux > 0x3f800000U ? __CLC_GENTYPE_NAN : ret; - ret = aux == 0x3f800000U ? spiby2 : ret; - ret = xexp < -14 ? x : ret; + __CLC_GENTYPE s = __clc_sqrt_fast(r); + __CLC_GENTYPE ret = + __clc_mad(0x1.ddcb02p-1f, 0x1.aee9d6p+0f, -2.0f * __clc_mad(s, u, s)); - return ret; + __CLC_GENTYPE xux = __clc_mad(ax, u, ax); + ret = ax < 0.5f ? xux : ret; + + return __clc_copysign(ret, x); } #elif __CLC_FPSIZE == 64 -_CLC_OVERLOAD _CLC_DEF __CLC_GENTYPE __clc_asin(__CLC_GENTYPE x) { - // 0x3c91a62633145c07 - const __CLC_GENTYPE piby2_tail = __CLC_FP_LIT(6.1232339957367660e-17); - // 0x3fe921fb54442d18 - const __CLC_GENTYPE hpiby2_head = 7.8539816339744831e-01; - // 0x3ff921fb54442d18 - const __CLC_GENTYPE piby2 = 1.5707963267948965e+00; - +static _CLC_OVERLOAD _CLC_CONST __CLC_GENTYPE __clc_asin_identity_reduction(__CLC_GENTYPE x, __CLC_GENTYPE r, + __CLC_GENTYPE u, __CLC_GENTYPE v) { __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); + __CLC_EP_PAIR s = __clc_ep_sqrt(r); + __CLC_EP_PAIR ve = __clc_ep_fast_sub( + __clc_ep_make_pair(__CLC_FP_LIT(0x1.921fb54442d18p-1), __CLC_FP_LIT(0x1.1a62633145c07p-55)), + __clc_ep_fast_add(s, __clc_ep_mul(s, u))); + v = ve.hi + ve.hi; + return y == 1.0 ? 0x1.921fb54442d18p+0 : v; +} - // abs(x) >= 0.5 - __CLC_LONGN transform = __CLC_CONVERT_LONGN(xexp >= -1); +_CLC_DEF _CLC_OVERLOAD _CLC_CONST __CLC_GENTYPE __clc_asin(__CLC_GENTYPE x) { + // Computes arcsin(x). + // The argument is first reduced by noting that arcsin(x) + // is invalid for abs(x) > 1 and arcsin(-x) = -arcsin(x). + // For denormal and small arguments arcsin(x) = x to machine + // accuracy. Remaining argument ranges are handled as follows. + // For abs(x) <= 0.5 use + // arcsin(x) = 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: + // arcsin(x) = pi/2 - 2*arcsin(sqrt(1-x)/2) + // together with the above rational approximation, and + // reconstruct the terms carefully. + + __CLC_GENTYPE y = __clc_fabs(x); + __CLC_S_GENTYPE transform = y >= 0.5; - __CLC_GENTYPE rt = __CLC_FP_LIT(0.5) * (__CLC_FP_LIT(1.0) - y); + __CLC_GENTYPE rt = __clc_mad(y, -0.5, 0.5); __CLC_GENTYPE y2 = y * y; __CLC_GENTYPE r = transform ? rt : y2; - // 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 asin carefully in transformed region - __CLC_GENTYPE s = __clc_sqrt(r); - __CLC_GENTYPE sh = - __CLC_AS_GENTYPE(__CLC_AS_ULONGN(s) & 0xffffffff00000000UL); - __CLC_GENTYPE c = MATH_DIVIDE(__clc_fma(-sh, sh, r), s + sh); - __CLC_GENTYPE p = __clc_fma(2.0 * s, u, -__clc_fma(-2.0, c, piby2_tail)); - __CLC_GENTYPE q = __clc_fma(-2.0, sh, hpiby2_head); - __CLC_GENTYPE vt = hpiby2_head - (p - q); - __CLC_GENTYPE v = __clc_fma(y, u, y); - v = transform ? vt : v; - - v = __CLC_CONVERT_LONGN(xexp < -28) ? y : v; - v = __CLC_CONVERT_LONGN(xexp >= 0) ? __CLC_GENTYPE_NAN : v; - v = y == 1.0 ? piby2 : v; - - return xneg ? -v : v; + __CLC_GENTYPE 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, + 0x1.059859fea6a70p-5, -0x1.0a5a378a05eafp-6), 0x1.4052137024d6ap-6), 0x1.ab3a098a70509p-8), + 0x1.8ed60a300c8d2p-7), 0x1.c6fa84b77012bp-7), 0x1.1c6c111dccb70p-6), 0x1.6e89f0a0adacfp-6), + 0x1.f1c72c668963fp-6), 0x1.6db6db41ce4bdp-5), 0x1.333333336fd5bp-4), 0x1.5555555555380p-3); + + __CLC_GENTYPE v = __clc_mad(y, u, y); + +#ifdef __CLC_SCALAR + if (transform) { + v = __clc_asin_identity_reduction(x, r, u, v); + } +#else + __CLC_GENTYPE identity = __clc_asin_identity_reduction(x, r, u, v); + v = transform ? identity : v; +#endif + + return __clc_copysign(v, x); } #elif __CLC_FPSIZE == 16 -_CLC_OVERLOAD _CLC_DEF __CLC_GENTYPE __clc_asin(__CLC_GENTYPE x) { - return __CLC_CONVERT_GENTYPE(__clc_asin(__CLC_CONVERT_FLOATN(x))); +static _CLC_OVERLOAD _CLC_CONST __CLC_GENTYPE +__clc_asin_small_case(__CLC_GENTYPE x) { + __CLC_HALFN ax = __clc_fabs(x); + __CLC_HALFN s = x * x; + __CLC_HALFN p = s * __clc_mad(s, 0x1.828p-4h, 0x1.52p-3h); + return __clc_mad(ax, p, ax); +} + +static _CLC_OVERLOAD _CLC_CONST __CLC_GENTYPE +__clc_asin_large_case(__CLC_GENTYPE x) { + __CLC_HALFN ax = __clc_fabs(x); + __CLC_FLOATN s = __clc_mad(__CLC_CONVERT_FLOATN(ax), (__CLC_FLOATN)-0.5f, + (__CLC_FLOATN)0.5f); + __CLC_FLOATN t = __clc_sqrt_fast(s); + __CLC_FLOATN p = __clc_mad(t, __clc_mad(s, -0x1.82675ap-2f, -0x1.ff9f6p+0f), + 0x1.921fb6p+0f); + return __CLC_CONVERT_HALFN(p); +} + +_CLC_DEF _CLC_OVERLOAD _CLC_CONST __CLC_GENTYPE __clc_asin(__CLC_GENTYPE x) { + // Computes arcsin(x). + // The argument is first reduced by noting that arcsin(x) + // is invalid for abs(x) > 1 and arcsin(-x) = -arcsin(x). + // For denormal and small arguments arcsin(x) = x to machine + // accuracy. Remaining argument ranges are handled as follows. + // For abs(x) <= 0.5 use + // arcsin(x) = x + x^3*R(x^2) + // where R(x^2) is a polynomial minimax approximation to + // (arcsin(x) - x)/x^3. + // For abs(x) > 0.5 exploit the identity: + // arcsin(x) = pi/2 - 2*arcsin(sqrt(1-x)/2) + // together with the above polynomial approximation, and + // reconstruct the terms carefully. + + __CLC_HALFN ax = __clc_fabs(x); + __CLC_HALFN r = + ax <= 0.5h ? __clc_asin_small_case(x) : __clc_asin_large_case(x); + return __clc_copysign(r, x); } #endif _______________________________________________ cfe-commits mailing list [email protected] https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
