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| | From 645b7635ba8fd58062245419e8bb668ab90cd3ec Mon Sep 17 00:00:00 2001
From: "Gabriel F. T. Gomes" <gftg@linux.vnet.ibm.com>
Date: Mon, 7 Aug 2017 09:14:14 -0300
Subject: [PATCH 09/90] powerpc: Restrict xssqrtqp operands to Vector Registers
(bug 21941)
POWER ISA 3.0 introduces the xssqrtqp instructions, which expects
operands to be in Vector Registers (Altivec/VMX), even though this
instruction belongs to the Vector-Scalar Instruction Set.
In GCC's Extended Assembly for POWER, the 'wq' register constraint is
provided for use with IEEE 754 128-bit floating-point values. However,
this constraint does not limit the register allocation to Vector
Registers (Altivec/VMX) and could assign a Vector-Scalar Register (VSX)
to the operands of the instruction.
This patch changes the register constraint used in sqrtf128 from 'wq' to
'v', in order to request a Vector Register (Altivec/VMX) for use with
the xssqrtqp instruction.
Tested for powerpc64le and --with-cpu=power9.
[BZ #21941]
* sysdeps/powerpc/fpu/math_private.h (__ieee754_sqrtf128): Since
xssqrtqp requires operands to be in Vector Registers
(Altivec/VMX), replace the register constraint 'wq' with 'v'.
* sysdeps/powerpc/powerpc64le/power9/fpu/e_sqrtf128.c
(__ieee754_sqrtf128): Likewise.
(cherry picked from commit 4d98ace9de3183309cb394cd0110eda5ad2d2531)
diff --git a/ChangeLog b/ChangeLog
index 0057c0902a..6886cd9361 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,12 @@
+2017-08-10 Gabriel F. T. Gomes <gftg@linux.vnet.ibm.com>
+
+ [BZ #21941]
+ * sysdeps/powerpc/fpu/math_private.h (__ieee754_sqrtf128): Since
+ xssqrtqp requires operands to be in Vector Registers
+ (Altivec/VMX), replace the register constraint 'wq' with 'v'.
+ * sysdeps/powerpc/powerpc64le/power9/fpu/e_sqrtf128.c
+ (__ieee754_sqrtf128): Likewise.
+
2017-08-11 Florian Weimer <fweimer@redhat.com>
[BZ #21242]
diff --git a/sysdeps/powerpc/fpu/math_private.h b/sysdeps/powerpc/fpu/math_private.h
index d8fd4923ac..396fd0562e 100644
--- a/sysdeps/powerpc/fpu/math_private.h
+++ b/sysdeps/powerpc/fpu/math_private.h
@@ -30,7 +30,7 @@ extern __always_inline _Float128
__ieee754_sqrtf128 (_Float128 __x)
{
_Float128 __z;
- asm ("xssqrtqp %0,%1" : "=wq" (__z) : "wq" (__x));
+ asm ("xssqrtqp %0,%1" : "=v" (__z) : "v" (__x));
return __z;
}
#endif
diff --git a/sysdeps/powerpc/powerpc64le/power9/fpu/e_sqrtf128.c b/sysdeps/powerpc/powerpc64le/power9/fpu/e_sqrtf128.c
index 769d3f8922..59fd8269f5 100644
--- a/sysdeps/powerpc/powerpc64le/power9/fpu/e_sqrtf128.c
+++ b/sysdeps/powerpc/powerpc64le/power9/fpu/e_sqrtf128.c
@@ -30,7 +30,7 @@ __float128
__ieee754_sqrtf128 (__float128 a)
{
__float128 z;
- asm ("xssqrtqp %0,%1" : "=wq" (z) : "wq" (a));
+ asm ("xssqrtqp %0,%1" : "=v" (z) : "v" (a));
return z;
}
strong_alias (__ieee754_sqrtf128, __sqrtf128_finite)
|