diff options
| -rw-r--r-- | lib/std/fltbits.myr | 31 | ||||
| -rw-r--r-- | lib/std/fltfmt.myr | 10 | ||||
| -rw-r--r-- | lib/std/test/fltbits.myr | 63 | ||||
| -rw-r--r-- | lib/std/test/fmt.myr | 1 |
4 files changed, 81 insertions, 24 deletions
diff --git a/lib/std/fltbits.myr b/lib/std/fltbits.myr index 81c3ef1..0f687ca 100644 --- a/lib/std/fltbits.myr +++ b/lib/std/fltbits.myr @@ -20,6 +20,9 @@ const flt32bits = {flt; -> (&flt : uint32#)#} const flt64frombits = {bits; -> (&bits : flt64#)#} const flt32frombits = {bits; -> (&bits : flt32#)#} +const Dblbias = 1023 +const Fltbias = 127 + const flt64explode = {flt var bits, isneg, mant, uexp, exp @@ -31,16 +34,10 @@ const flt64explode = {flt /* add back the implicit bit if this is not a denormal */ if uexp != 0 mant |= 1ul << 52 - exp = (uexp : int64) - else - exp = 1 ;; - /* - adjust for exponent bias. nb: because we are - treating the mantissa as m.0 instead of 0.m, - our exponent bias needs to be offset by the - size of m - */ + + /* adjust for exponent bias */ + exp = (uexp : int64) - Dblbias -> (isneg, mant, exp) } @@ -55,16 +52,10 @@ const flt32explode = {flt /* add back the implicit bit if this is not a denormal */ if uexp != 0 mant |= 1 << 23 - exp = (uexp : int32) - else - exp = 1 ;; - /* - adjust for exponent bias. nb: because we are - treating the mantissa as m.0 instead of 0.m, - our exponent bias needs to be offset by the - size of m - */ + + /* adjust for exponent bias */ + exp = (uexp : int32) - Fltbias -> (isneg, mant, exp) } @@ -72,7 +63,7 @@ const flt64assem = {sign, mant, exp var s, m, e s = (sign : uint64) - e = (exp : uint64) & 0x7ff + e = (exp + Dblbias : uint64) & 0x7ff m = (mant : uint64) & ((1ul<<52) - 1) -> std.flt64frombits((s << 63) | (e << 52) | m) } @@ -81,7 +72,7 @@ const flt32assem = {sign, mant, exp var s, m, e s = (sign : uint32) - e = (exp : uint32) & 0xff + e = (exp + Fltbias : uint32) & 0xff m = (mant : uint32) & ((1<<23) - 1) -> std.flt32frombits(s << 31 | e << 23 | m) diff --git a/lib/std/fltfmt.myr b/lib/std/fltfmt.myr index b0c08c4..9988c06 100644 --- a/lib/std/fltfmt.myr +++ b/lib/std/fltfmt.myr @@ -25,13 +25,15 @@ const flt64bfmt = {sb, val, mode, precision var isneg, exp, mant (isneg, mant, exp) = flt64explode(val) - dragon4(sb, isneg, mant, (exp - 52 : int64), Dblbias, mode, precision) + exp = max(exp, 1 - Dblbias) + dragon4(sb, isneg, mant, exp - 52, Dblbias, mode, precision) } const flt32bfmt = {sb, val, mode, precision var isneg, exp, mant (isneg, mant, exp) = flt32explode(val) + exp = (max((exp : int64), 1 - Fltbias) : int32) dragon4(sb, isneg, (mant : uint64), (exp - 23 : int64), Fltbias, mode, precision) } @@ -64,9 +66,9 @@ const dragon4 = {sb, isneg, f, e, p, mode, cutoff /* initialize */ roundup = false u = mkbigint(0) - r = bigshli(mkbigint(f), max(e - p, 0)) - s = bigshli(mkbigint(1), max(0, -(e - p))) - mm = bigshli(mkbigint(1), max((e - p), 0)) + r = bigshli(mkbigint(f), max(e, 0)) + s = bigshli(mkbigint(1), max(0, -e)) + mm = bigshli(mkbigint(1), max(e, 0)) mp = bigdup(mm) /* fixup: unequal gaps */ diff --git a/lib/std/test/fltbits.myr b/lib/std/test/fltbits.myr index 6e3b7c3..1354c70 100644 --- a/lib/std/test/fltbits.myr +++ b/lib/std/test/fltbits.myr @@ -9,6 +9,8 @@ const main = { [.name = "bits-roundtrip-64", .fn = bitsround64], [.name = "flt32bits", .fn = flt32bits], [.name = "flt64bits", .fn = flt64bits], + [.name = "explode-roundtrip-32", .fn = exploderound32], + [.name = "explode-roundtrip-64", .fn = exploderound64], ][:]) } @@ -96,3 +98,64 @@ const flt64bits = {c testr.check(c, u == uprime, "flt64bits wrong for {}: 0x{x} != 0x{x}", f, u, uprime) ;; } + +const exploderound32 = {c + for f : [1.0, 0.00001, 123.45, 1111111111111111.2, -1.9, -0.0001, std.flt32nan()][:] + var n, e, s + (n, e, s) = std.flt32explode(f) + var g = std.flt32assem(n, e, s) + testr.check(c, f == g, "assem o explode non-identity: {} != {}", f, g) + ;; + + /* + The exponents and significands need to be rather specific + in order for flt32assem to work as expected + */ + for (n, e, s) : [ + (false, 0, -127), + (true, 0, -127), + (false, 0x399, -127), + (true, 0x23, -127), + (false, (1 << 23) | 0x23, 45), + (true, (1 << 23) | 0x3a2, -12), + (true, (1 << 23) | 0x3a1, -126), + ][:] + var m, f, t + (m, f, t) = std.flt32explode(std.flt32assem(n, e, s)) + testr.check(c, n == m, "explode o assem non-identity: {} != {}", (n, e, s), (m, f, t)) + testr.check(c, e == f, "explode o assem non-identity: {} != {}", (n, e, s), (m, f, t)) + testr.check(c, s == t, "explode o assem non-identity: {} != {}", (n, e, s), (m, f, t)) + ;; +} + +const exploderound64 = {c + for f : [1.0, 0.00001, 123.45, 1111111111111e+309, -1.9, -0.0001, std.flt64nan()][:] + var n, e, s + (n, e, s) = std.flt64explode(f) + var g = std.flt64assem(n, e, s) + testr.check(c, f == g, "assem o explode non-identity: {} != {}", f, g) + ;; + + /* + The exponents and significands need to be rather specific + in order for flt32assem to work as expected + */ + for (n, e, s) : [ + (false, 0, -1023), + (true, 0, -1023), + (false, 0x399, -1023), + (true, 0x23, -1023), + (false, (1 << 52) | 0xa33bc, 45), + (true, (1 << 52) | 0x3, -12), + (true, (1 << 52) | 0x11aabbcc, -200), + (true, (1 << 52) | 0x3a1, 543), + (true, (1 << 52) | 0x99aa228, 1001), + ][:] + var m, f, t + (m, f, t) = std.flt64explode(std.flt64assem(n, e, s)) + testr.check(c, n == m, "explode o assem non-identity: {} != {}", (n, e, s), (m, f, t)) + testr.check(c, e == f, "explode o assem non-identity: {} != {}", (n, e, s), (m, f, t)) + testr.check(c, s == t, "explode o assem non-identity: {} != {}", (n, e, s), (m, f, t)) + ;; +} + diff --git a/lib/std/test/fmt.myr b/lib/std/test/fmt.myr index da1b76a..acf499f 100644 --- a/lib/std/test/fmt.myr +++ b/lib/std/test/fmt.myr @@ -66,6 +66,7 @@ const builtins = { check("7b", "{x}", 123) check("0x7b", "0x{x}", 123) check("0.0", "{}", 0.0) + check("-0.0", "{}", -0.0) check("0.3", "{}", 0.3) check("0.3", "{}", (0.3 : flt32)) check("1.0", "{}", 1.0) |