[libclc] 0effa7c - libclc: Update asinpi (#188454)
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Wed Mar 25 03:27:21 PDT 2026
Author: Matt Arsenault
Date: 2026-03-25T10:27:09Z
New Revision: 0effa7caf1263b4ca7fccb2b6b1953b363923375
URL: https://github.com/llvm/llvm-project/commit/0effa7caf1263b4ca7fccb2b6b1953b363923375
DIFF: https://github.com/llvm/llvm-project/commit/0effa7caf1263b4ca7fccb2b6b1953b363923375.diff
LOG: libclc: Update asinpi (#188454)
This was originally ported from rocm device libs in
eea0997566cad3be13df897a06dfda74cbd684b9. Update for more recent
changes.
Added:
Modified:
libclc/clc/lib/generic/math/clc_asinpi.cl
libclc/clc/lib/generic/math/clc_asinpi.inc
Removed:
################################################################################
diff --git a/libclc/clc/lib/generic/math/clc_asinpi.cl b/libclc/clc/lib/generic/math/clc_asinpi.cl
index cad756266bb0a..1350376668acc 100644
--- a/libclc/clc/lib/generic/math/clc_asinpi.cl
+++ b/libclc/clc/lib/generic/math/clc_asinpi.cl
@@ -7,13 +7,12 @@
//===----------------------------------------------------------------------===//
#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/math.h"
+#include "clc/math/clc_sqrt_fast.h"
#define __CLC_BODY "clc_asinpi.inc"
#include "clc/math/gentype.inc"
diff --git a/libclc/clc/lib/generic/math/clc_asinpi.inc b/libclc/clc/lib/generic/math/clc_asinpi.inc
index 2a47b8ed4591f..336c42b4c0adf 100644
--- a/libclc/clc/lib/generic/math/clc_asinpi.inc
+++ b/libclc/clc/lib/generic/math/clc_asinpi.inc
@@ -27,130 +27,131 @@
#if __CLC_FPSIZE == 32
-_CLC_OVERLOAD _CLC_DEF __CLC_GENTYPE __clc_asinpi(__CLC_GENTYPE x) {
- const __CLC_GENTYPE pi = __CLC_FP_LIT(3.1415926535897933e+00);
- // 0x33a22168
- const __CLC_GENTYPE piby2_tail = __CLC_FP_LIT(7.5497894159e-08);
- // 0x3f490fda
- const __CLC_GENTYPE hpiby2_head = __CLC_FP_LIT(7.8539812565e-01);
+_CLC_DEF _CLC_OVERLOAD _CLC_CONST __CLC_FLOATN __clc_asinpi(__CLC_FLOATN 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.
+
+ const __CLC_FLOATN piinv = 0x1.45f306p-2f;
+
+ __CLC_FLOATN ax = __clc_fabs(x);
+
+ __CLC_FLOATN tx = __clc_mad(ax, -0.5f, 0.5f);
+ __CLC_FLOATN x2 = ax * ax;
+ __CLC_FLOATN r = ax >= 0.5f ? tx : x2;
+
+ __CLC_FLOATN u = r * __clc_mad(r, __clc_mad(r, __clc_mad(r, __clc_mad(r,
+ __clc_mad(r,
+ -0x1.3f1c6cp-8f, 0x1.2ac560p-6f), 0x1.80aab4p-8f), 0x1.e53378p-7f),
+ 0x1.86680ap-6f), 0x1.b29c5ap-5f);
- __CLC_UINTN ux = __CLC_AS_UINTN(x);
- __CLC_UINTN aux = ux & EXSIGNBIT_SP32;
- __CLC_UINTN xs = ux ^ aux;
- __CLC_GENTYPE shalf =
- __CLC_AS_GENTYPE(xs | __CLC_AS_UINTN(__CLC_FP_LIT(0.5)));
+ __CLC_FLOATN s = __clc_sqrt_fast(r);
+ __CLC_FLOATN ret = __clc_mad(-2.0f, __clc_mad(s, u, piinv * s), 0.5f);
+ __CLC_FLOATN xux = __clc_mad(piinv, ax, ax * u);
+ ret = ax >= 0.5f ? ret : xux;
- __CLC_INTN xexp = __CLC_AS_INTN(aux >> EXPSHIFTBITS_SP32) - EXPBIAS_SP32;
+ return __clc_copysign(ret, x);
+}
- __CLC_GENTYPE y = __CLC_AS_GENTYPE(aux);
+#elif __CLC_FPSIZE == 64
- // abs(x) >= 0.5
- __CLC_INTN transform = xexp >= -1;
+#define piinv (__CLC_DOUBLEN)0x1.45f306dc9c883p-2
- __CLC_GENTYPE y2 = y * y;
- __CLC_GENTYPE rt = 0.5f * (1.0f - y);
- __CLC_GENTYPE r = transform ? rt : y2;
+static _CLC_OVERLOAD _CLC_CONST __CLC_DOUBLEN __clc_asinpi_identity(
+ __CLC_DOUBLEN x, __CLC_DOUBLEN r, __CLC_DOUBLEN u, __CLC_DOUBLEN v) {
+ __CLC_DOUBLEN y = __clc_fabs(x);
+ __CLC_EP_PAIR s = __clc_ep_ldexp(__clc_ep_sqrt(r), 1);
+ __CLC_EP_PAIR ve = __clc_ep_fast_sub(
+ 0.5, __clc_ep_fast_add(__clc_ep_mul(piinv, s), __clc_ep_mul(s, u)));
+ v = ve.hi;
+ return y == 1.0 ? 0.5 : v;
+}
- // Use a rational approximation for [0.0, 0.5]
- __CLC_GENTYPE a =
- __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;
- v = MATH_DIVIDE(v, pi);
- __CLC_GENTYPE xbypi = MATH_DIVIDE(x, pi);
-
- __CLC_GENTYPE ret = __CLC_AS_GENTYPE(xs | __CLC_AS_UINTN(v));
- ret = aux > 0x3f800000U ? __CLC_GENTYPE_NAN : ret;
- ret = aux == 0x3f800000U ? shalf : ret;
- ret = xexp < -14 ? xbypi : ret;
-
- return ret;
+_CLC_DEF _CLC_OVERLOAD _CLC_CONST __CLC_DOUBLEN __clc_asinpi(__CLC_DOUBLEN 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_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 v = __clc_mad(y, piinv, y * u);
+ v = transform ? __clc_asinpi_identity(x, r, u, v) : v;
+
+ return __clc_copysign(v, x);
}
-#elif __CLC_FPSIZE == 64
+#undef piinv
+
+#elif __CLC_FPSIZE == 16
-_CLC_OVERLOAD _CLC_DEF __CLC_GENTYPE __clc_asinpi(__CLC_GENTYPE x) {
- const __CLC_GENTYPE pi = __CLC_FP_LIT(0x1.921fb54442d18p+1);
- // 0x3c91a62633145c07
- const __CLC_GENTYPE piby2_tail = __CLC_FP_LIT(6.1232339957367660e-17);
- // 0x3fe921fb54442d18
- const __CLC_GENTYPE hpiby2_head = __CLC_FP_LIT(7.8539816339744831e-01);
-
- __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);
-
- __CLC_GENTYPE rt = 0.5 * (1.0 - y);
- __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 = MATH_DIVIDE(v, pi);
- v = __CLC_CONVERT_LONGN(xexp >= 0) ? __CLC_GENTYPE_NAN : v;
- v = y == 1.0 ? 0.5 : v;
- return xneg ? -v : v;
+static _CLC_OVERLOAD _CLC_CONST __CLC_HALFN __clc_asinpi_small(__CLC_HALFN x) {
+ __CLC_HALFN ax = __clc_fabs(x);
+ __CLC_HALFN s = x * x;
+ return ax * __clc_mad(s, __clc_mad(s, 0x1.0b8p-5h, 0x1.a7cp-5h), 0x1.46p-2h);
}
-#elif __CLC_FPSIZE == 16
+static _CLC_OVERLOAD _CLC_CONST __CLC_HALFN __clc_asinpi_large(__CLC_HALFN x) {
+ __CLC_HALFN ax = __clc_fabs(x);
+ __CLC_FLOATN s = __clc_mad(__CLC_CONVERT_FLOATN(ax), -0.5f, 0.5f);
+ __CLC_FLOATN t = __clc_sqrt_fast(s);
+ __CLC_FLOATN p =
+ __clc_mad(t,
+ __clc_mad(s, __clc_mad(s, -0x1.f4b736p-5f, -0x1.ad0826p-4f),
+ -0x1.45f5a8p-1f),
+ 0.5f);
+ return __CLC_CONVERT_HALFN(p);
+}
-_CLC_OVERLOAD _CLC_DEF __CLC_GENTYPE __clc_asinpi(__CLC_GENTYPE x) {
- return __CLC_CONVERT_GENTYPE(__clc_asinpi(__CLC_CONVERT_FLOATN(x)));
+_CLC_DEF _CLC_OVERLOAD _CLC_CONST __CLC_HALFN __clc_asinpi(__CLC_HALFN 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_asinpi_small(x) : __clc_asinpi_large(x);
+ return __clc_copysign(r, x);
}
#endif
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