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| author | Gabriel F. T. Gomes <gftg@linux.vnet.ibm.com> | 2017-08-07 09:14:14 -0300 |
|---|---|---|
| committer | Gabriel F. T. Gomes <gftg@linux.vnet.ibm.com> | 2017-08-10 16:10:21 -0300 |
| commit | 4d98ace9de3183309cb394cd0110eda5ad2d2531 (patch) | |
| tree | f6467c5c3fa12f02f563e3d5d126ec1a6658e903 /sysdeps | |
| parent | 922369032c604b4dcfd535e1bcddd4687e7126a5 (diff) | |
| download | glibc-4d98ace9de3183309cb394cd0110eda5ad2d2531.zip glibc-4d98ace9de3183309cb394cd0110eda5ad2d2531.tar.gz glibc-4d98ace9de3183309cb394cd0110eda5ad2d2531.tar.bz2 | |
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.
Diffstat (limited to 'sysdeps')
| -rw-r--r-- | sysdeps/powerpc/fpu/math_private.h | 2 | ||||
| -rw-r--r-- | sysdeps/powerpc/powerpc64le/power9/fpu/e_sqrtf128.c | 2 |
2 files changed, 2 insertions, 2 deletions
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) |