From 74d022f975f22fda20c0d1fe09a3f6fc7680f64f Mon Sep 17 00:00:00 2001 From: Bor Grošelj Simić Date: Fri, 28 Jan 2022 02:06:17 +0100 Subject: implement unsigned -> float casts amd64 lacks an instruction for this so it has to be implemented with signed -> float casts: - Word casting is done by zero-extending the word to a long and then doing a regular signed cast. - Long casting is done by dividing by two with correct rounding if the highest bit is set and casting that to float, then adding 1 to mantissa with integer addition --- amd64/isel.c | 45 +++++++++++++++++++++++++++++++++++++++++++-- 1 file changed, 43 insertions(+), 2 deletions(-) (limited to 'amd64/isel.c') diff --git a/amd64/isel.c b/amd64/isel.c index 404b714..17ab86d 100644 --- a/amd64/isel.c +++ b/amd64/isel.c @@ -201,8 +201,8 @@ selcmp(Ref arg[2], int k, int swap, Fn *fn) static void sel(Ins i, ANum *an, Fn *fn) { - Ref r0, r1; - int x, k, kc, swap; + Ref r0, r1, tmp[7]; + int x, j, k, kc, swap; int64_t sz; Ins *i0, *i1; @@ -266,6 +266,47 @@ sel(Ins i, ANum *an, Fn *fn) emit(Ocopy, Kw, TMP(RCX), r0, R); fixarg(&i1->arg[0], argcls(&i, 0), i1, fn); break; + case Ouwtof: + r0 = newtmp("utof", Kl, fn); + emit(Osltof, k, i.to, r0, R); + emit(Oextuw, Kl, r0, i.arg[0], R); + fixarg(&curi->arg[0], k, curi, fn); + break; + case Oultof: + /* + %mask =l and %arg.0, 1 + %isbig =l shr %arg.0, 63 + %divided =l shr %arg.0, %isbig + %or =l or %mask, %divided + %float =d sltof %or + %cast =l cast %float + %addend =l shl %isbig, 52 + %sum =l add %cast, %addend + %result =d cast %sum + */ + r0 = newtmp("utof", k, fn); + if (k == Ks) + kc = Kw; + else + kc = Kl; + for (j=0; j<4; j++) + tmp[j] = newtmp("utof", Kl, fn); + for (; j<7; j++) + tmp[j] = newtmp("utof", kc, fn); + emit(Ocast, k, i.to, tmp[6], R); + emit(Oadd, kc, tmp[6], tmp[4], tmp[5]); + emit(Oshl, kc, tmp[5], tmp[1], getcon(k == Ks ? 23 : 52, fn)); + emit(Ocast, kc, tmp[4], r0, R); + + emit(Osltof, k, r0, tmp[3], R); + emit(Oor, Kl, tmp[3], tmp[0], tmp[2]); + emit(Oshr, Kl, tmp[2], i.arg[0], tmp[1]); + sel(*curi++, an, fn); + emit(Oshr, Kl, tmp[1], i.arg[0], getcon(63, fn)); + fixarg(&curi->arg[0], Kl, curi, fn); + emit(Oand, Kl, tmp[0], i.arg[0], getcon(1, fn)); + fixarg(&curi->arg[0], Kl, curi, fn); + break; case Onop: break; case Ostored: -- cgit 1.4.1