[llvm-branch-commits] [libclc] libclc: Update atanh (PR #188225)
Matt Arsenault via llvm-branch-commits
llvm-branch-commits at lists.llvm.org
Tue Mar 24 04:22:30 PDT 2026
https://github.com/arsenm created https://github.com/llvm/llvm-project/pull/188225
None
>From fcdd4d2694d90325ec8b63b7153e274a33d9d57f Mon Sep 17 00:00:00 2001
From: Matt Arsenault <Matthew.Arsenault at amd.com>
Date: Sat, 21 Mar 2026 21:51:29 +0100
Subject: [PATCH] libclc: Update atanh
---
libclc/clc/lib/generic/math/clc_atanh.cl | 11 ++-
libclc/clc/lib/generic/math/clc_atanh.inc | 112 ++++++----------------
2 files changed, 36 insertions(+), 87 deletions(-)
diff --git a/libclc/clc/lib/generic/math/clc_atanh.cl b/libclc/clc/lib/generic/math/clc_atanh.cl
index 456a3ac2624c3..312f1e3306b17 100644
--- a/libclc/clc/lib/generic/math/clc_atanh.cl
+++ b/libclc/clc/lib/generic/math/clc_atanh.cl
@@ -8,12 +8,13 @@
#include "clc/clc_convert.h"
#include "clc/float/definitions.h"
-#include "clc/internal/clc.h"
+#include "clc/math/clc_atanh.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_log1p.h"
-#include "clc/math/clc_mad.h"
-#include "clc/math/math.h"
+#include "clc/math/clc_log2_fast.h"
+#include "clc/math/clc_recip_fast.h"
+#include "clc/relational/clc_isnan.h"
#define __CLC_BODY "clc_atanh.inc"
#include "clc/math/gentype.inc"
diff --git a/libclc/clc/lib/generic/math/clc_atanh.inc b/libclc/clc/lib/generic/math/clc_atanh.inc
index e76f340d8cd94..fc2c20a2bae07 100644
--- a/libclc/clc/lib/generic/math/clc_atanh.inc
+++ b/libclc/clc/lib/generic/math/clc_atanh.inc
@@ -8,98 +8,46 @@
#if __CLC_FPSIZE == 32
-_CLC_OVERLOAD _CLC_DEF __CLC_GENTYPE __clc_atanh(__CLC_GENTYPE x) {
- __CLC_UINTN ux = __CLC_AS_UINTN(x);
- __CLC_UINTN ax = ux & EXSIGNBIT_SP32;
- __CLC_UINTN xs = ux ^ ax;
-
- // |x| > 1 or NaN
- __CLC_GENTYPE z = __CLC_GENTYPE_NAN;
-
- // |x| == 1
- __CLC_GENTYPE t = __CLC_AS_GENTYPE(xs | PINFBITPATT_SP32);
- z = ax == 0x3f800000U ? t : z;
-
- // 1/2 <= |x| < 1
- t = __CLC_AS_GENTYPE(ax);
- t = MATH_DIVIDE(2.0f * t, 1.0f - t);
- t = 0.5f * __clc_log1p(t);
- t = __CLC_AS_GENTYPE(xs | __CLC_AS_UINTN(t));
- z = ax < 0x3f800000U ? t : z;
-
- // |x| < 1/2
- t = x * x;
- __CLC_GENTYPE a = __clc_mad(
- __clc_mad(0.92834212715e-2f, t, -0.28120347286e0f), t, 0.39453629046e0f);
- __CLC_GENTYPE b = __clc_mad(__clc_mad(0.45281890445e0f, t, -0.15537744551e1f),
- t, 0.11836088638e1f);
- __CLC_GENTYPE p = MATH_DIVIDE(a, b);
- t = __clc_mad(x * t, p, x);
- z = ax < 0x3f000000 ? t : z;
-
- // |x| < 2^-13
- z = ax < 0x39000000U ? x : z;
-
- return z;
+_CLC_DEF _CLC_OVERLOAD _CLC_CONST __CLC_FLOATN __clc_atanh(__CLC_FLOATN x) {
+ __CLC_FLOATN y = __clc_fabs(x);
+ __CLC_EP_PAIR a =
+ __clc_ep_fast_div(__clc_ep_fast_add(1.0f, y), __clc_ep_fast_sub(1.0f, y));
+ __CLC_FLOATN z = 0.5f * __clc_ep_ln_hi(a, 0);
+ z = y < 0x1.0p-12f ? y : z;
+
+ z = y > 1.0f ? FLT_NAN : z;
+ z = y == 1.0f ? __CLC_GENTYPE_INF : z;
+ return __clc_copysign(z, x);
}
#elif __CLC_FPSIZE == 64
-_CLC_OVERLOAD _CLC_DEF __CLC_GENTYPE __clc_atanh(__CLC_GENTYPE x) {
- __CLC_GENTYPE absx = __clc_fabs(x);
-
- __CLC_GENTYPE ret = absx == 1.0
- ? __CLC_AS_GENTYPE((__CLC_ULONGN)PINFBITPATT_DP64)
- : __CLC_GENTYPE_NAN;
+_CLC_DEF _CLC_OVERLOAD _CLC_CONST __CLC_DOUBLEN __clc_atanh(__CLC_DOUBLEN x) {
+ __CLC_DOUBLEN y = __clc_fabs(x);
+ __CLC_EP_PAIR a =
+ __clc_ep_fast_div(__clc_ep_fast_add(1.0, y), __clc_ep_fast_sub(1.0, y));
+ __CLC_DOUBLEN z = 0.5 * __clc_ep_ln_hi(a, 0);
+ z = y < 0x1.0p-27 ? y : z;
- // |x| >= 0.5
- // Note that atanh(x) = 0.5 * ln((1+x)/(1-x))
- // For greater accuracy we use
- // ln((1+x)/(1-x)) = ln(1 + 2x/(1-x)) = log1p(2x/(1-x)).
- __CLC_GENTYPE r = 0.5 * __clc_log1p(2.0 * absx / (1.0 - absx));
- ret = absx < 1.0 ? r : ret;
+ z = y > 1.0 ? DBL_NAN : z;
+ z = y == 1.0 ? __CLC_GENTYPE_INF : z;
- r = -ret;
- ret = x < 0.0 ? r : ret;
-
- // Arguments up to 0.5 in magnitude are
- // approximated by a [5,5] minimax polynomial
- __CLC_GENTYPE t = x * x;
-
- __CLC_GENTYPE pn = __clc_fma(
- t,
- __clc_fma(t,
- __clc_fma(t,
- __clc_fma(t,
- __clc_fma(t, -0.10468158892753136958e-3,
- 0.28728638600548514553e-1),
- -0.28180210961780814148e0),
- 0.88468142536501647470e0),
- -0.11028356797846341457e1),
- 0.47482573589747356373e0);
-
- __CLC_GENTYPE pd = __clc_fma(
- t,
- __clc_fma(t,
- __clc_fma(t,
- __clc_fma(t,
- __clc_fma(t, -0.35861554370169537512e-1,
- 0.49561196555503101989e0),
- -0.22608883748988489342e1),
- 0.45414700626084508355e1),
- -0.41631933639693546274e1),
- 0.14244772076924206909e1);
-
- r = __clc_fma(x * t, pn / pd, x);
- ret = absx < 0.5 ? r : ret;
-
- return ret;
+ return __clc_copysign(z, x);
}
#elif __CLC_FPSIZE == 16
-_CLC_OVERLOAD _CLC_DEF __CLC_GENTYPE __clc_atanh(__CLC_GENTYPE x) {
- return __CLC_CONVERT_GENTYPE(__clc_atanh(__CLC_CONVERT_FLOATN(x)));
+_CLC_DEF _CLC_OVERLOAD _CLC_CONST __CLC_HALFN __clc_atanh(__CLC_HALFN x) {
+ __CLC_HALFN absx = __clc_fabs(x);
+ __CLC_FLOATN absxf = __CLC_CONVERT_FLOATN(absx);
+ __CLC_FLOATN t = (1.0f + absxf) * __clc_recip_fast(1.0f - absxf);
+ __CLC_HALFN ret = __CLC_CONVERT_HALFN(__clc_log2_fast(t) * 0x1.62e430p-2f);
+ ret = absx < 0x1.0p-7h ? absx : ret;
+
+ ret = absx == 1.0h ? __CLC_GENTYPE_INF : ret;
+ ret = (absx > 1.0h) || __clc_isnan(absx) ? HALF_NAN : ret;
+
+ return __clc_copysign(ret, x);
}
#endif
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