From 645b7635ba8fd58062245419e8bb668ab90cd3ec Mon Sep 17 00:00:00 2001 From: "Gabriel F. T. Gomes" Date: Mon, 7 Aug 2017 09:14:14 -0300 Subject: [PATCH 09] 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) --- ChangeLog | 9 +++++++++ sysdeps/powerpc/fpu/math_private.h | 2 +- sysdeps/powerpc/powerpc64le/power9/fpu/e_sqrtf128.c | 2 +- 3 files changed, 11 insertions(+), 2 deletions(-) diff --git a/ChangeLog b/ChangeLog index 0057c09..6886cd9 100644 --- a/ChangeLog +++ b/ChangeLog @@ -1,3 +1,12 @@ +2017-08-10 Gabriel F. T. Gomes + + [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 [BZ #21242] diff --git a/sysdeps/powerpc/fpu/math_private.h b/sysdeps/powerpc/fpu/math_private.h index d8fd492..396fd05 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 769d3f8..59fd826 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) -- 2.7.4.GIT