From fdcc625376505eacb1125a6aeba57501407a30ec Mon Sep 17 00:00:00 2001
From: Andrew Waterman <andrew@sifive.com>
Date: Thu, 22 Feb 2018 14:31:54 -0500
Subject: RISC-V: fmax/fmin: Handle signalling NaNs correctly.

RISC-V's fmax(sNAN,4) returns 4 but glibc expects it to return qNAN.

	* sysdeps/riscv/rvd/s_fmax.c (__fmax): Handle sNaNs correctly.
	* sysdeps/riscv/rvd/s_fmin.c (__fmin): Likewise.
	* sysdeps/riscv/rvf/s_fmaxf.c (__fmaxf): Likewise.
	* sysdeps/riscv/rvf/s_fminf.c (__fminf): Likewise.
---
 sysdeps/riscv/rvf/s_fmaxf.c | 11 +++++++++--
 sysdeps/riscv/rvf/s_fminf.c | 11 +++++++++--
 2 files changed, 18 insertions(+), 4 deletions(-)

(limited to 'sysdeps/riscv/rvf')

diff --git a/sysdeps/riscv/rvf/s_fmaxf.c b/sysdeps/riscv/rvf/s_fmaxf.c
index 3293f2f..63f7e3d 100644
--- a/sysdeps/riscv/rvf/s_fmaxf.c
+++ b/sysdeps/riscv/rvf/s_fmaxf.c
@@ -17,12 +17,19 @@
    <http://www.gnu.org/licenses/>.  */
 
 #include <math.h>
+#include <math_private.h>
 #include <libm-alias-float.h>
 
 float
 __fmaxf (float x, float y)
 {
-  asm ("fmax.s %0, %1, %2" : "=f" (x) : "f" (x), "f" (y));
-  return x;
+  float res;
+
+  if (__glibc_unlikely ((_FCLASS (x) | _FCLASS (y)) & _FCLASS_SNAN))
+    return x + y;
+  else
+    asm ("fmax.s %0, %1, %2" : "=f" (res) : "f" (x), "f" (y));
+
+  return res;
 }
 libm_alias_float (__fmax, fmax)
diff --git a/sysdeps/riscv/rvf/s_fminf.c b/sysdeps/riscv/rvf/s_fminf.c
index e4411f0..82cca4e 100644
--- a/sysdeps/riscv/rvf/s_fminf.c
+++ b/sysdeps/riscv/rvf/s_fminf.c
@@ -17,12 +17,19 @@
    <http://www.gnu.org/licenses/>.  */
 
 #include <math.h>
+#include <math_private.h>
 #include <libm-alias-float.h>
 
 float
 __fminf (float x, float y)
 {
-  asm ("fmin.s %0, %1, %2" : "=f" (x) : "f" (x), "f" (y));
-  return x;
+  float res;
+
+  if (__glibc_unlikely ((_FCLASS (x) | _FCLASS (y)) & _FCLASS_SNAN))
+    return x + y;
+  else
+    asm ("fmin.s %0, %1, %2" : "=f" (res) : "f" (x), "f" (y));
+
+  return res;
 }
 libm_alias_float (__fmin, fmin)
-- 
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