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From: Vineet Gupta <Vineet.Gupta1@synopsys.com>
To: libc-alpha@sourceware.org
Cc: Vineet Gupta <Vineet.Gupta1@synopsys.com>,
	linux-snps-arc@lists.infradead.org,
	Adhemerval Zanella <adhemerval.zanella@linaro.org>
Subject: [PATCH v2 1/4] iee754: provide gcc builtins based generic sqrt functions
Date: Mon,  1 Jun 2020 17:35:38 -0700	[thread overview]
Message-ID: <20200602003541.21005-2-vgupta@synopsys.com> (raw)
In-Reply-To: <20200602003541.21005-1-vgupta@synopsys.com>

Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
---
 sysdeps/generic/math-use-builtins.h |  3 +++
 sysdeps/ieee754/dbl-64/e_sqrt.c     |  6 ++++++
 sysdeps/ieee754/flt-32/e_sqrtf.c    | 16 ++++++++++------
 3 files changed, 19 insertions(+), 6 deletions(-)

diff --git a/sysdeps/generic/math-use-builtins.h b/sysdeps/generic/math-use-builtins.h
index 8a39ef58bc95..fc724c824a17 100644
--- a/sysdeps/generic/math-use-builtins.h
+++ b/sysdeps/generic/math-use-builtins.h
@@ -60,4 +60,7 @@
 # define USE_COPYSIGNF128_BUILTIN 0
 #endif
 
+#define USE_SQRT_BUILTIN 0
+#define USE_SQRTF_BUILTIN 0
+
 #endif /* math-use-builtins.h */
diff --git a/sysdeps/ieee754/dbl-64/e_sqrt.c b/sysdeps/ieee754/dbl-64/e_sqrt.c
index d42a1a4eb6e9..518a8ae5cdaf 100644
--- a/sysdeps/ieee754/dbl-64/e_sqrt.c
+++ b/sysdeps/ieee754/dbl-64/e_sqrt.c
@@ -41,6 +41,7 @@
 #include <math_private.h>
 #include <fenv_private.h>
 #include <libm-alias-finite.h>
+#include <math-use-builtins.h>
 
 /*********************************************************************/
 /* An ultimate sqrt routine. Given an IEEE double machine number x   */
@@ -50,6 +51,10 @@
 double
 __ieee754_sqrt (double x)
 {
+#if USE_SQRT_BUILTIN
+  return __builtin_sqrt (x);
+#else
+  /* Use generic implementation.  */
   static const double
     rt0 = 9.99999999859990725855365213134618E-01,
     rt1 = 4.99999999495955425917856814202739E-01,
@@ -138,6 +143,7 @@ __ieee754_sqrt (double x)
 	return (x - x) / (x - x); /* sqrt(-ve)=sNaN */
       return 0x1p-256 * __ieee754_sqrt (x * 0x1p512);
     }
+#endif /* ! USE_SQRT_BUILTIN  */
 }
 #ifndef __ieee754_sqrt
 libm_alias_finite (__ieee754_sqrt, __sqrt)
diff --git a/sysdeps/ieee754/flt-32/e_sqrtf.c b/sysdeps/ieee754/flt-32/e_sqrtf.c
index b339444301aa..d85a04162983 100644
--- a/sysdeps/ieee754/flt-32/e_sqrtf.c
+++ b/sysdeps/ieee754/flt-32/e_sqrtf.c
@@ -16,12 +16,15 @@
 #include <math.h>
 #include <math_private.h>
 #include <libm-alias-finite.h>
-
-static	const float	one	= 1.0, tiny=1.0e-30;
+#include <math-use-builtins.h>
 
 float
 __ieee754_sqrtf(float x)
 {
+#if USE_SQRTF_BUILTIN
+	return __builtin_sqrtf (x);
+#else
+	/* Use generic implementation.  */
 	float z;
 	int32_t sign = (int)0x80000000;
 	int32_t ix,s,q,m,t,i;
@@ -70,10 +73,10 @@ __ieee754_sqrtf(float x)
 
     /* use floating add to find out rounding direction */
 	if(ix!=0) {
-	    z = one-tiny; /* trigger inexact flag */
-	    if (z>=one) {
-		z = one+tiny;
-		if (z>one)
+	    z = 0x1p0 - 0x1.4484cp-100; /* trigger inexact flag */
+	    if (z >= 0x1p0) {
+		z = 0x1p0 + 0x1.4484cp-100;
+		if (z > 0x1p0)
 		    q += 2;
 		else
 		    q += (q&1);
@@ -83,6 +86,7 @@ __ieee754_sqrtf(float x)
 	ix += (m <<23);
 	SET_FLOAT_WORD(z,ix);
 	return z;
+#endif /* ! USE_SQRTF_BUILTIN  */
 }
 #ifndef __ieee754_sqrtf
 libm_alias_finite (__ieee754_sqrtf, __sqrtf)
-- 
2.20.1


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  reply	other threads:[~2020-06-02  0:35 UTC|newest]

Thread overview: 13+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-06-02  0:35 [PATCH v2 0/4] Enable generic math code for more arches Vineet Gupta
2020-06-02  0:35 ` Vineet Gupta [this message]
     [not found]   ` <5d912d39-f017-31fa-990b-e1c1b735e1ff@linux.ibm.com>
2020-06-02 16:54     ` [PATCH v2 1/4] iee754: provide gcc builtins based generic sqrt functions Vineet Gupta
2020-06-02 17:17   ` Adhemerval Zanella
2020-06-02  0:35 ` [PATCH v2 2/4] iee754: provide gcc builtins based generic fma functions Vineet Gupta
     [not found]   ` <34fc6c13-65e6-dcbb-42b1-1ba9f56b4dfd@linux.ibm.com>
2020-06-02 17:13     ` Vineet Gupta
     [not found]       ` <d6813e17-3847-7fd2-45e8-23576b62061d@linaro.org>
2020-06-03  0:20         ` Vineet Gupta
2020-06-03  6:29       ` Stefan Liebler
2020-06-02 17:28   ` Adhemerval Zanella
2020-06-02  0:35 ` [PATCH v2 3/4] aarch/fpu: use generic builtins based math functions Vineet Gupta
2020-06-02 17:31   ` Adhemerval Zanella
2020-06-02 19:14     ` Vineet Gupta
2020-06-02  0:35 ` [PATCH v2 4/4] powerpc/fpu: use generic fma functions Vineet Gupta

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