diff options
-rw-r--r-- | arch/mips/math-emu/Makefile | 4 | ||||
-rw-r--r-- | arch/mips/math-emu/cp1emu.c | 48 | ||||
-rw-r--r-- | arch/mips/math-emu/dp_fmax.c | 213 | ||||
-rw-r--r-- | arch/mips/math-emu/ieee754.h | 4 | ||||
-rw-r--r-- | arch/mips/math-emu/sp_fmax.c | 213 |
5 files changed, 480 insertions, 2 deletions
diff --git a/arch/mips/math-emu/Makefile b/arch/mips/math-emu/Makefile index b9946322804e..a19641d3ac23 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_2008class.o dp_fmin.o \ + dp_tint.o dp_fint.o dp_maddf.o dp_msubf.o dp_2008class.o dp_fmin.o dp_fmax.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_2008class.o sp_fmin.o \ + sp_tint.o sp_fint.o sp_maddf.o sp_msubf.o sp_2008class.o sp_fmin.o sp_fmax.o \ dsemul.o lib-y += ieee754d.o \ diff --git a/arch/mips/math-emu/cp1emu.c b/arch/mips/math-emu/cp1emu.c index f397bdfd93fb..32f0e19a0d7f 100644 --- a/arch/mips/math-emu/cp1emu.c +++ b/arch/mips/math-emu/cp1emu.c @@ -1839,6 +1839,30 @@ static int fpu_emu(struct pt_regs *xcp, struct mips_fpu_struct *ctx, break; } + case fmax_op: { + union ieee754sp fs, ft; + + if (!cpu_has_mips_r6) + return SIGILL; + + SPFROMREG(ft, MIPSInst_FT(ir)); + SPFROMREG(fs, MIPSInst_FS(ir)); + rv.s = ieee754sp_fmax(fs, ft); + break; + } + + case fmaxa_op: { + union ieee754sp fs, ft; + + if (!cpu_has_mips_r6) + return SIGILL; + + SPFROMREG(ft, MIPSInst_FT(ir)); + SPFROMREG(fs, MIPSInst_FS(ir)); + rv.s = ieee754sp_fmaxa(fs, ft); + break; + } + case fabs_op: handler.u = ieee754sp_abs; goto scopuop; @@ -2133,6 +2157,30 @@ copcsr: break; } + case fmax_op: { + union ieee754dp fs, ft; + + if (!cpu_has_mips_r6) + return SIGILL; + + DPFROMREG(ft, MIPSInst_FT(ir)); + DPFROMREG(fs, MIPSInst_FS(ir)); + rv.d = ieee754dp_fmax(fs, ft); + break; + } + + case fmaxa_op: { + union ieee754dp fs, ft; + + if (!cpu_has_mips_r6) + return SIGILL; + + DPFROMREG(ft, MIPSInst_FT(ir)); + DPFROMREG(fs, MIPSInst_FS(ir)); + rv.d = ieee754dp_fmaxa(fs, ft); + break; + } + case fabs_op: handler.u = ieee754dp_abs; goto dcopuop; diff --git a/arch/mips/math-emu/dp_fmax.c b/arch/mips/math-emu/dp_fmax.c new file mode 100644 index 000000000000..fd71b8daaaf2 --- /dev/null +++ b/arch/mips/math-emu/dp_fmax.c @@ -0,0 +1,213 @@ +/* + * IEEE754 floating point arithmetic + * double precision: MIN{,A}.f + * MIN : Scalar Floating-Point Minimum + * MINA: Scalar Floating-Point argument with Minimum Absolute Value + * + * MIN.D : FPR[fd] = minNum(FPR[fs],FPR[ft]) + * MINA.D: FPR[fd] = maxNumMag(FPR[fs],FPR[ft]) + * + * MIPS floating point support + * Copyright (C) 2015 Imagination Technologies, Ltd. + * Author: Markos Chandras <markos.chandras@imgtec.com> + * + * 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" + +union ieee754dp ieee754dp_fmax(union ieee754dp x, union ieee754dp y) +{ + COMPXDP; + COMPYDP; + + EXPLODEXDP; + EXPLODEYDP; + + FLUSHXDP; + FLUSHYDP; + + ieee754_clearcx(); + + switch (CLPAIR(xc, yc)) { + case CLPAIR(IEEE754_CLASS_QNAN, IEEE754_CLASS_SNAN): + case CLPAIR(IEEE754_CLASS_ZERO, IEEE754_CLASS_SNAN): + case CLPAIR(IEEE754_CLASS_NORM, IEEE754_CLASS_SNAN): + case CLPAIR(IEEE754_CLASS_DNORM, IEEE754_CLASS_SNAN): + case CLPAIR(IEEE754_CLASS_INF, IEEE754_CLASS_SNAN): + return ieee754dp_nanxcpt(y); + + case CLPAIR(IEEE754_CLASS_SNAN, IEEE754_CLASS_SNAN): + case CLPAIR(IEEE754_CLASS_SNAN, IEEE754_CLASS_QNAN): + case CLPAIR(IEEE754_CLASS_SNAN, IEEE754_CLASS_ZERO): + case CLPAIR(IEEE754_CLASS_SNAN, IEEE754_CLASS_NORM): + case CLPAIR(IEEE754_CLASS_SNAN, IEEE754_CLASS_DNORM): + case CLPAIR(IEEE754_CLASS_SNAN, IEEE754_CLASS_INF): + return ieee754dp_nanxcpt(x); + + /* numbers are preferred to NaNs */ + case CLPAIR(IEEE754_CLASS_ZERO, IEEE754_CLASS_QNAN): + case CLPAIR(IEEE754_CLASS_NORM, IEEE754_CLASS_QNAN): + case CLPAIR(IEEE754_CLASS_DNORM, IEEE754_CLASS_QNAN): + case CLPAIR(IEEE754_CLASS_INF, IEEE754_CLASS_QNAN): + return x; + + case CLPAIR(IEEE754_CLASS_QNAN, IEEE754_CLASS_QNAN): + case CLPAIR(IEEE754_CLASS_QNAN, IEEE754_CLASS_ZERO): + case CLPAIR(IEEE754_CLASS_QNAN, IEEE754_CLASS_NORM): + case CLPAIR(IEEE754_CLASS_QNAN, IEEE754_CLASS_DNORM): + case CLPAIR(IEEE754_CLASS_QNAN, IEEE754_CLASS_INF): + return y; + + /* + * Infinity and zero handling + */ + case CLPAIR(IEEE754_CLASS_INF, IEEE754_CLASS_ZERO): + case CLPAIR(IEEE754_CLASS_INF, IEEE754_CLASS_NORM): + case CLPAIR(IEEE754_CLASS_INF, IEEE754_CLASS_DNORM): + case CLPAIR(IEEE754_CLASS_NORM, IEEE754_CLASS_ZERO): + case CLPAIR(IEEE754_CLASS_DNORM, IEEE754_CLASS_ZERO): + return xs ? y : x; + + case CLPAIR(IEEE754_CLASS_INF, IEEE754_CLASS_INF): + case CLPAIR(IEEE754_CLASS_NORM, IEEE754_CLASS_INF): + case CLPAIR(IEEE754_CLASS_DNORM, IEEE754_CLASS_INF): + case CLPAIR(IEEE754_CLASS_ZERO, IEEE754_CLASS_INF): + case CLPAIR(IEEE754_CLASS_ZERO, IEEE754_CLASS_NORM): + case CLPAIR(IEEE754_CLASS_ZERO, IEEE754_CLASS_DNORM): + return ys ? x : y; + + case CLPAIR(IEEE754_CLASS_ZERO, IEEE754_CLASS_ZERO): + if (xs == ys) + return x; + return ieee754dp_zero(1); + + case CLPAIR(IEEE754_CLASS_DNORM, IEEE754_CLASS_DNORM): + DPDNORMX; + + case CLPAIR(IEEE754_CLASS_NORM, IEEE754_CLASS_DNORM): + DPDNORMY; + break; + + case CLPAIR(IEEE754_CLASS_DNORM, IEEE754_CLASS_NORM): + DPDNORMX; + } + + /* Finally get to do some computation */ + + assert(xm & DP_HIDDEN_BIT); + assert(ym & DP_HIDDEN_BIT); + + /* Compare signs */ + if (xs > ys) + return y; + else if (xs < ys) + return x; + + /* Compare exponent */ + if (xe > ye) + return x; + else if (xe < ye) + return y; + + /* Compare mantissa */ + if (xm <= ym) + return y; + return x; +} + +union ieee754dp ieee754dp_fmaxa(union ieee754dp x, union ieee754dp y) +{ + COMPXDP; + COMPYDP; + + EXPLODEXDP; + EXPLODEYDP; + + FLUSHXDP; + FLUSHYDP; + + ieee754_clearcx(); + + switch (CLPAIR(xc, yc)) { + case CLPAIR(IEEE754_CLASS_QNAN, IEEE754_CLASS_SNAN): + case CLPAIR(IEEE754_CLASS_ZERO, IEEE754_CLASS_SNAN): + case CLPAIR(IEEE754_CLASS_NORM, IEEE754_CLASS_SNAN): + case CLPAIR(IEEE754_CLASS_DNORM, IEEE754_CLASS_SNAN): + case CLPAIR(IEEE754_CLASS_INF, IEEE754_CLASS_SNAN): + return ieee754dp_nanxcpt(y); + + case CLPAIR(IEEE754_CLASS_SNAN, IEEE754_CLASS_SNAN): + case CLPAIR(IEEE754_CLASS_SNAN, IEEE754_CLASS_QNAN): + case CLPAIR(IEEE754_CLASS_SNAN, IEEE754_CLASS_ZERO): + case CLPAIR(IEEE754_CLASS_SNAN, IEEE754_CLASS_NORM): + case CLPAIR(IEEE754_CLASS_SNAN, IEEE754_CLASS_DNORM): + case CLPAIR(IEEE754_CLASS_SNAN, IEEE754_CLASS_INF): + return ieee754dp_nanxcpt(x); + + /* numbers are preferred to NaNs */ + case CLPAIR(IEEE754_CLASS_ZERO, IEEE754_CLASS_QNAN): + case CLPAIR(IEEE754_CLASS_NORM, IEEE754_CLASS_QNAN): + case CLPAIR(IEEE754_CLASS_DNORM, IEEE754_CLASS_QNAN): + case CLPAIR(IEEE754_CLASS_INF, IEEE754_CLASS_QNAN): + return x; + + case CLPAIR(IEEE754_CLASS_QNAN, IEEE754_CLASS_QNAN): + case CLPAIR(IEEE754_CLASS_QNAN, IEEE754_CLASS_ZERO): + case CLPAIR(IEEE754_CLASS_QNAN, IEEE754_CLASS_NORM): + case CLPAIR(IEEE754_CLASS_QNAN, IEEE754_CLASS_DNORM): + case CLPAIR(IEEE754_CLASS_QNAN, IEEE754_CLASS_INF): + return y; + + /* + * Infinity and zero handling + */ + case CLPAIR(IEEE754_CLASS_INF, IEEE754_CLASS_ZERO): + case CLPAIR(IEEE754_CLASS_INF, IEEE754_CLASS_NORM): + case CLPAIR(IEEE754_CLASS_INF, IEEE754_CLASS_DNORM): + case CLPAIR(IEEE754_CLASS_NORM, IEEE754_CLASS_ZERO): + case CLPAIR(IEEE754_CLASS_DNORM, IEEE754_CLASS_ZERO): + return x; + + case CLPAIR(IEEE754_CLASS_INF, IEEE754_CLASS_INF): + case CLPAIR(IEEE754_CLASS_NORM, IEEE754_CLASS_INF): + case CLPAIR(IEEE754_CLASS_DNORM, IEEE754_CLASS_INF): + case CLPAIR(IEEE754_CLASS_ZERO, IEEE754_CLASS_INF): + case CLPAIR(IEEE754_CLASS_ZERO, IEEE754_CLASS_NORM): + case CLPAIR(IEEE754_CLASS_ZERO, IEEE754_CLASS_DNORM): + return y; + + case CLPAIR(IEEE754_CLASS_ZERO, IEEE754_CLASS_ZERO): + if (xs == ys) + return x; + return ieee754dp_zero(1); + + case CLPAIR(IEEE754_CLASS_DNORM, IEEE754_CLASS_DNORM): + DPDNORMX; + + case CLPAIR(IEEE754_CLASS_NORM, IEEE754_CLASS_DNORM): + DPDNORMY; + break; + + case CLPAIR(IEEE754_CLASS_DNORM, IEEE754_CLASS_NORM): + DPDNORMX; + } + + /* Finally get to do some computation */ + + assert(xm & DP_HIDDEN_BIT); + assert(ym & DP_HIDDEN_BIT); + + /* Compare exponent */ + if (xe > ye) + return x; + else if (xe < ye) + return y; + + /* Compare mantissa */ + if (xm <= ym) + return y; + return x; +} diff --git a/arch/mips/math-emu/ieee754.h b/arch/mips/math-emu/ieee754.h index 6a16357a1ddd..df94720714c7 100644 --- a/arch/mips/math-emu/ieee754.h +++ b/arch/mips/math-emu/ieee754.h @@ -82,6 +82,8 @@ union ieee754sp ieee754sp_msubf(union ieee754sp z, union ieee754sp x, int ieee754sp_2008class(union ieee754sp x); union ieee754sp ieee754sp_fmin(union ieee754sp x, union ieee754sp y); union ieee754sp ieee754sp_fmina(union ieee754sp x, union ieee754sp y); +union ieee754sp ieee754sp_fmax(union ieee754sp x, union ieee754sp y); +union ieee754sp ieee754sp_fmaxa(union ieee754sp x, union ieee754sp y); /* * double precision (often aka double) @@ -114,6 +116,8 @@ union ieee754dp ieee754dp_msubf(union ieee754dp z, union ieee754dp x, int ieee754dp_2008class(union ieee754dp x); union ieee754dp ieee754dp_fmin(union ieee754dp x, union ieee754dp y); union ieee754dp ieee754dp_fmina(union ieee754dp x, union ieee754dp y); +union ieee754dp ieee754dp_fmax(union ieee754dp x, union ieee754dp y); +union ieee754dp ieee754dp_fmaxa(union ieee754dp x, union ieee754dp y); /* 5 types of floating point number diff --git a/arch/mips/math-emu/sp_fmax.c b/arch/mips/math-emu/sp_fmax.c new file mode 100644 index 000000000000..4d000844e48e --- /dev/null +++ b/arch/mips/math-emu/sp_fmax.c @@ -0,0 +1,213 @@ +/* + * IEEE754 floating point arithmetic + * single precision: MAX{,A}.f + * MAX : Scalar Floating-Point Maximum + * MAXA: Scalar Floating-Point argument with Maximum Absolute Value + * + * MAX.S : FPR[fd] = maxNum(FPR[fs],FPR[ft]) + * MAXA.S: FPR[fd] = maxNumMag(FPR[fs],FPR[ft]) + * + * MIPS floating point support + * Copyright (C) 2015 Imagination Technologies, Ltd. + * Author: Markos Chandras <markos.chandras@imgtec.com> + * + * 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" + +union ieee754sp ieee754sp_fmax(union ieee754sp x, union ieee754sp y) +{ + COMPXSP; + COMPYSP; + + EXPLODEXSP; + EXPLODEYSP; + + FLUSHXSP; + FLUSHYSP; + + ieee754_clearcx(); + + switch (CLPAIR(xc, yc)) { + case CLPAIR(IEEE754_CLASS_QNAN, IEEE754_CLASS_SNAN): + case CLPAIR(IEEE754_CLASS_ZERO, IEEE754_CLASS_SNAN): + case CLPAIR(IEEE754_CLASS_NORM, IEEE754_CLASS_SNAN): + case CLPAIR(IEEE754_CLASS_DNORM, IEEE754_CLASS_SNAN): + case CLPAIR(IEEE754_CLASS_INF, IEEE754_CLASS_SNAN): + return ieee754sp_nanxcpt(y); + + case CLPAIR(IEEE754_CLASS_SNAN, IEEE754_CLASS_SNAN): + case CLPAIR(IEEE754_CLASS_SNAN, IEEE754_CLASS_QNAN): + case CLPAIR(IEEE754_CLASS_SNAN, IEEE754_CLASS_ZERO): + case CLPAIR(IEEE754_CLASS_SNAN, IEEE754_CLASS_NORM): + case CLPAIR(IEEE754_CLASS_SNAN, IEEE754_CLASS_DNORM): + case CLPAIR(IEEE754_CLASS_SNAN, IEEE754_CLASS_INF): + return ieee754sp_nanxcpt(x); + + /* numbers are preferred to NaNs */ + case CLPAIR(IEEE754_CLASS_ZERO, IEEE754_CLASS_QNAN): + case CLPAIR(IEEE754_CLASS_NORM, IEEE754_CLASS_QNAN): + case CLPAIR(IEEE754_CLASS_DNORM, IEEE754_CLASS_QNAN): + case CLPAIR(IEEE754_CLASS_INF, IEEE754_CLASS_QNAN): + return x; + + case CLPAIR(IEEE754_CLASS_QNAN, IEEE754_CLASS_QNAN): + case CLPAIR(IEEE754_CLASS_QNAN, IEEE754_CLASS_ZERO): + case CLPAIR(IEEE754_CLASS_QNAN, IEEE754_CLASS_NORM): + case CLPAIR(IEEE754_CLASS_QNAN, IEEE754_CLASS_DNORM): + case CLPAIR(IEEE754_CLASS_QNAN, IEEE754_CLASS_INF): + return y; + + /* + * Infinity and zero handling + */ + case CLPAIR(IEEE754_CLASS_INF, IEEE754_CLASS_ZERO): + case CLPAIR(IEEE754_CLASS_INF, IEEE754_CLASS_NORM): + case CLPAIR(IEEE754_CLASS_INF, IEEE754_CLASS_DNORM): + case CLPAIR(IEEE754_CLASS_NORM, IEEE754_CLASS_ZERO): + case CLPAIR(IEEE754_CLASS_DNORM, IEEE754_CLASS_ZERO): + return xs ? y : x; + + case CLPAIR(IEEE754_CLASS_INF, IEEE754_CLASS_INF): + case CLPAIR(IEEE754_CLASS_NORM, IEEE754_CLASS_INF): + case CLPAIR(IEEE754_CLASS_DNORM, IEEE754_CLASS_INF): + case CLPAIR(IEEE754_CLASS_ZERO, IEEE754_CLASS_INF): + case CLPAIR(IEEE754_CLASS_ZERO, IEEE754_CLASS_NORM): + case CLPAIR(IEEE754_CLASS_ZERO, IEEE754_CLASS_DNORM): + return ys ? x : y; + + case CLPAIR(IEEE754_CLASS_ZERO, IEEE754_CLASS_ZERO): + if (xs == ys) + return x; + return ieee754sp_zero(1); + + case CLPAIR(IEEE754_CLASS_DNORM, IEEE754_CLASS_DNORM): + SPDNORMX; + + case CLPAIR(IEEE754_CLASS_NORM, IEEE754_CLASS_DNORM): + SPDNORMY; + break; + + case CLPAIR(IEEE754_CLASS_DNORM, IEEE754_CLASS_NORM): + SPDNORMX; + } + + /* Finally get to do some computation */ + + assert(xm & SP_HIDDEN_BIT); + assert(ym & SP_HIDDEN_BIT); + + /* Compare signs */ + if (xs > ys) + return y; + else if (xs < ys) + return x; + + /* Compare exponent */ + if (xe > ye) + return x; + else if (xe < ye) + return y; + + /* Compare mantissa */ + if (xm <= ym) + return y; + return x; +} + +union ieee754sp ieee754sp_fmaxa(union ieee754sp x, union ieee754sp y) +{ + COMPXSP; + COMPYSP; + + EXPLODEXSP; + EXPLODEYSP; + + FLUSHXSP; + FLUSHYSP; + + ieee754_clearcx(); + + switch (CLPAIR(xc, yc)) { + case CLPAIR(IEEE754_CLASS_QNAN, IEEE754_CLASS_SNAN): + case CLPAIR(IEEE754_CLASS_ZERO, IEEE754_CLASS_SNAN): + case CLPAIR(IEEE754_CLASS_NORM, IEEE754_CLASS_SNAN): + case CLPAIR(IEEE754_CLASS_DNORM, IEEE754_CLASS_SNAN): + case CLPAIR(IEEE754_CLASS_INF, IEEE754_CLASS_SNAN): + return ieee754sp_nanxcpt(y); + + case CLPAIR(IEEE754_CLASS_SNAN, IEEE754_CLASS_SNAN): + case CLPAIR(IEEE754_CLASS_SNAN, IEEE754_CLASS_QNAN): + case CLPAIR(IEEE754_CLASS_SNAN, IEEE754_CLASS_ZERO): + case CLPAIR(IEEE754_CLASS_SNAN, IEEE754_CLASS_NORM): + case CLPAIR(IEEE754_CLASS_SNAN, IEEE754_CLASS_DNORM): + case CLPAIR(IEEE754_CLASS_SNAN, IEEE754_CLASS_INF): + return ieee754sp_nanxcpt(x); + + /* numbers are preferred to NaNs */ + case CLPAIR(IEEE754_CLASS_ZERO, IEEE754_CLASS_QNAN): + case CLPAIR(IEEE754_CLASS_NORM, IEEE754_CLASS_QNAN): + case CLPAIR(IEEE754_CLASS_DNORM, IEEE754_CLASS_QNAN): + case CLPAIR(IEEE754_CLASS_INF, IEEE754_CLASS_QNAN): + return x; + + case CLPAIR(IEEE754_CLASS_QNAN, IEEE754_CLASS_QNAN): + case CLPAIR(IEEE754_CLASS_QNAN, IEEE754_CLASS_ZERO): + case CLPAIR(IEEE754_CLASS_QNAN, IEEE754_CLASS_NORM): + case CLPAIR(IEEE754_CLASS_QNAN, IEEE754_CLASS_DNORM): + case CLPAIR(IEEE754_CLASS_QNAN, IEEE754_CLASS_INF): + return y; + + /* + * Infinity and zero handling + */ + case CLPAIR(IEEE754_CLASS_INF, IEEE754_CLASS_ZERO): + case CLPAIR(IEEE754_CLASS_INF, IEEE754_CLASS_NORM): + case CLPAIR(IEEE754_CLASS_INF, IEEE754_CLASS_DNORM): + case CLPAIR(IEEE754_CLASS_NORM, IEEE754_CLASS_ZERO): + case CLPAIR(IEEE754_CLASS_DNORM, IEEE754_CLASS_ZERO): + return x; + + case CLPAIR(IEEE754_CLASS_INF, IEEE754_CLASS_INF): + case CLPAIR(IEEE754_CLASS_NORM, IEEE754_CLASS_INF): + case CLPAIR(IEEE754_CLASS_DNORM, IEEE754_CLASS_INF): + case CLPAIR(IEEE754_CLASS_ZERO, IEEE754_CLASS_INF): + case CLPAIR(IEEE754_CLASS_ZERO, IEEE754_CLASS_NORM): + case CLPAIR(IEEE754_CLASS_ZERO, IEEE754_CLASS_DNORM): + return y; + + case CLPAIR(IEEE754_CLASS_ZERO, IEEE754_CLASS_ZERO): + if (xs == ys) + return x; + return ieee754sp_zero(1); + + case CLPAIR(IEEE754_CLASS_DNORM, IEEE754_CLASS_DNORM): + SPDNORMX; + + case CLPAIR(IEEE754_CLASS_NORM, IEEE754_CLASS_DNORM): + SPDNORMY; + break; + + case CLPAIR(IEEE754_CLASS_DNORM, IEEE754_CLASS_NORM): + SPDNORMX; + } + + /* Finally get to do some computation */ + + assert(xm & SP_HIDDEN_BIT); + assert(ym & SP_HIDDEN_BIT); + + /* Compare exponent */ + if (xe > ye) + return x; + else if (xe < ye) + return y; + + /* Compare mantissa */ + if (xm <= ym) + return y; + return x; +} |