From 38db37ba069f9d801ef56b820cfc7c247a7ffc02 Mon Sep 17 00:00:00 2001 From: Markos Chandras Date: Thu, 13 Aug 2015 09:56:34 +0200 Subject: [PATCH] MIPS: math-emu: Add support for the MIPS R6 CLASS FPU instruction MIPS R6 introduced the following instruction: Stores in fd a bit mask reflecting the floating-point class of the floating point scalar value fs. CLASS.fmt: FPR[fd] = class(FPR[fs]) Signed-off-by: Markos Chandras Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/10959/ Signed-off-by: Ralf Baechle --- arch/mips/math-emu/Makefile | 4 +-- arch/mips/math-emu/cp1emu.c | 24 +++++++++++++++++ arch/mips/math-emu/dp_2008class.c | 55 +++++++++++++++++++++++++++++++++++++++ arch/mips/math-emu/ieee754.h | 2 ++ arch/mips/math-emu/sp_2008class.c | 55 +++++++++++++++++++++++++++++++++++++++ 5 files changed, 138 insertions(+), 2 deletions(-) create mode 100644 arch/mips/math-emu/dp_2008class.c create mode 100644 arch/mips/math-emu/sp_2008class.c diff --git a/arch/mips/math-emu/Makefile b/arch/mips/math-emu/Makefile index 0037690..ea8db26 100644 --- a/arch/mips/math-emu/Makefile +++ b/arch/mips/math-emu/Makefile @@ -4,9 +4,9 @@ obj-y += cp1emu.o ieee754dp.o ieee754sp.o ieee754.o \ dp_div.o dp_mul.o dp_sub.o dp_add.o dp_fsp.o dp_cmp.o dp_simple.o \ - dp_tint.o dp_fint.o dp_maddf.o dp_msubf.o \ + dp_tint.o dp_fint.o dp_maddf.o dp_msubf.o dp_2008class.o \ sp_div.o sp_mul.o sp_sub.o sp_add.o sp_fdp.o sp_cmp.o sp_simple.o \ - sp_tint.o sp_fint.o sp_maddf.o sp_msubf.o \ + sp_tint.o sp_fint.o sp_maddf.o sp_msubf.o sp_2008class.o \ dsemul.o lib-y += ieee754d.o \ diff --git a/arch/mips/math-emu/cp1emu.c b/arch/mips/math-emu/cp1emu.c index a348cbe..b65b4ea 100644 --- a/arch/mips/math-emu/cp1emu.c +++ b/arch/mips/math-emu/cp1emu.c @@ -1803,6 +1803,18 @@ static int fpu_emu(struct pt_regs *xcp, struct mips_fpu_struct *ctx, goto copcsr; } + case fclass_op: { + union ieee754sp fs; + + if (!cpu_has_mips_r6) + return SIGILL; + + SPFROMREG(fs, MIPSInst_FS(ir)); + rv.w = ieee754sp_2008class(fs); + rfmt = w_fmt; + break; + } + case fabs_op: handler.u = ieee754sp_abs; goto scopuop; @@ -2061,6 +2073,18 @@ copcsr: goto copcsr; } + case fclass_op: { + union ieee754dp fs; + + if (!cpu_has_mips_r6) + return SIGILL; + + DPFROMREG(fs, MIPSInst_FS(ir)); + rv.w = ieee754dp_2008class(fs); + rfmt = w_fmt; + break; + } + case fabs_op: handler.u = ieee754dp_abs; goto dcopuop; diff --git a/arch/mips/math-emu/dp_2008class.c b/arch/mips/math-emu/dp_2008class.c new file mode 100644 index 0000000..9dc39fc --- /dev/null +++ b/arch/mips/math-emu/dp_2008class.c @@ -0,0 +1,55 @@ +/* + * IEEE754 floating point arithmetic + * double precision: CLASS.f + * FPR[fd] = class(FPR[fs]) + * + * MIPS floating point support + * Copyright (C) 2015 Imagination Technologies, Ltd. + * Author: Markos Chandras + * + * This program is free software; you can distribute it and/or modify it + * under the terms of the GNU General Public License as published by the + * Free Software Foundation; version 2 of the License. + */ + +#include "ieee754dp.h" + +int ieee754dp_2008class(union ieee754dp x) +{ + COMPXDP; + + EXPLODEXDP; + + /* + * 10 bit mask as follows: + * + * bit0 = SNAN + * bit1 = QNAN + * bit2 = -INF + * bit3 = -NORM + * bit4 = -DNORM + * bit5 = -ZERO + * bit6 = INF + * bit7 = NORM + * bit8 = DNORM + * bit9 = ZERO + */ + + switch(xc) { + case IEEE754_CLASS_SNAN: + return 0x01; + case IEEE754_CLASS_QNAN: + return 0x02; + case IEEE754_CLASS_INF: + return 0x04 << (xs ? 0 : 4); + case IEEE754_CLASS_NORM: + return 0x08 << (xs ? 0 : 4); + case IEEE754_CLASS_DNORM: + return 0x10 << (xs ? 0 : 4); + case IEEE754_CLASS_ZERO: + return 0x20 << (xs ? 0 : 4); + default: + pr_err("Unknown class: %d\n", xc); + return 0; + } +} diff --git a/arch/mips/math-emu/ieee754.h b/arch/mips/math-emu/ieee754.h index 8c78019..3b833ea 100644 --- a/arch/mips/math-emu/ieee754.h +++ b/arch/mips/math-emu/ieee754.h @@ -79,6 +79,7 @@ union ieee754sp ieee754sp_maddf(union ieee754sp z, union ieee754sp x, union ieee754sp y); union ieee754sp ieee754sp_msubf(union ieee754sp z, union ieee754sp x, union ieee754sp y); +int ieee754sp_2008class(union ieee754sp x); /* * double precision (often aka double) @@ -108,6 +109,7 @@ union ieee754dp ieee754dp_maddf(union ieee754dp z, union ieee754dp x, union ieee754dp y); union ieee754dp ieee754dp_msubf(union ieee754dp z, union ieee754dp x, union ieee754dp y); +int ieee754dp_2008class(union ieee754dp x); /* 5 types of floating point number diff --git a/arch/mips/math-emu/sp_2008class.c b/arch/mips/math-emu/sp_2008class.c new file mode 100644 index 0000000..ff62606 --- /dev/null +++ b/arch/mips/math-emu/sp_2008class.c @@ -0,0 +1,55 @@ +/* + * IEEE754 floating point arithmetic + * single precision: CLASS.f + * FPR[fd] = class(FPR[fs]) + * + * MIPS floating point support + * Copyright (C) 2015 Imagination Technologies, Ltd. + * Author: Markos Chandras + * + * This program is free software; you can distribute it and/or modify it + * under the terms of the GNU General Public License as published by the + * Free Software Foundation; version 2 of the License. + */ + +#include "ieee754sp.h" + +int ieee754sp_2008class(union ieee754sp x) +{ + COMPXSP; + + EXPLODEXSP; + + /* + * 10 bit mask as follows: + * + * bit0 = SNAN + * bit1 = QNAN + * bit2 = -INF + * bit3 = -NORM + * bit4 = -DNORM + * bit5 = -ZERO + * bit6 = INF + * bit7 = NORM + * bit8 = DNORM + * bit9 = ZERO + */ + + switch(xc) { + case IEEE754_CLASS_SNAN: + return 0x01; + case IEEE754_CLASS_QNAN: + return 0x02; + case IEEE754_CLASS_INF: + return 0x04 << (xs ? 0 : 4); + case IEEE754_CLASS_NORM: + return 0x08 << (xs ? 0 : 4); + case IEEE754_CLASS_DNORM: + return 0x10 << (xs ? 0 : 4); + case IEEE754_CLASS_ZERO: + return 0x20 << (xs ? 0 : 4); + default: + pr_err("Unknown class: %d\n", xc); + return 0; + } +} -- 2.7.4