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FPU: Implement fdiv[s]

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This implements floating-point division A/B by a process that starts
with normalizing both inputs if necessary.  Then an estimate of 1/B
from a lookup table is refined by 3 Newton-Raphson iterations and then
multiplied by A to get a quotient.  The remainder is calculated as
A - R * B (where R is the result, i.e. the quotient) and the remainder
is compared to 0 and to B to see whether the quotient needs to be
incremented by 1.  The calculations of 1 / B are done with 56 fraction
bits and intermediate results are truncated rather than rounded,
meaning that the final estimate of 1 / B is always correct or a little
bit low, never too high, and thus the calculated quotient is correct
or 1 unit too low.  Doing the estimate of 1 / B with sufficient
precision that the quotient is always correct to the last bit without
needing any adjustment would require many more bits of precision.

This implements fdivs by computing a double-precision quotient and
then rounding it to single precision.  It would be possible to
optimize this by e.g. doing only 2 iterations of Newton-Raphson and
then doing the remainder calculation and adjustment at single
precision rather than double precision.

Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
pull/245/head
Paul Mackerras 4 years ago
parent e6a5f237bc
commit 9cce936251
5 changed files with 323 additions and 11 deletions
Show Stats Download Patch File Download Diff File

2
decode1.vhdl
Unescape Escape View File

@ -416,6 +416,7 @@ architecture behaviour of decode1 is
-- unit internal in1 in2 in3 out CR CR inv inv cry cry ldst BR sgn upd rsrv 32b sgn rc lk sgl
-- op in out A out in out len ext pipe
2#01110# => (FPU, OP_FPOP_I, NONE, FRB, NONE, FRT, '0', '0', '0', '0', ZERO, '0', NONE, '0', '0', '0', '0', '1', '0', RC, '0', '0'), -- fcfid[u]s
2#10010# => (FPU, OP_FPOP, FRA, FRB, NONE, FRT, '0', '0', '0', '0', ZERO, '0', NONE, '0', '0', '0', '0', '1', '0', RC, '0', '0'), -- fdivs
2#10100# => (FPU, OP_FPOP, FRA, FRB, NONE, FRT, '0', '0', '0', '0', ZERO, '0', NONE, '0', '0', '0', '0', '1', '0', RC, '0', '0'), -- fsubs
2#10101# => (FPU, OP_FPOP, FRA, FRB, NONE, FRT, '0', '0', '0', '0', ZERO, '0', NONE, '0', '0', '0', '0', '1', '0', RC, '0', '0'), -- fadds
2#11001# => (FPU, OP_FPOP, FRA, NONE, FRC, FRT, '0', '0', '0', '0', ZERO, '0', NONE, '0', '0', '0', '0', '1', '0', RC, '0', '0'), -- fmuls
@ -469,6 +470,7 @@ architecture behaviour of decode1 is
constant decode_op_63h_array : op_63_subop_array_1_t := (
-- unit internal in1 in2 in3 out CR CR inv inv cry cry ldst BR sgn upd rsrv 32b sgn rc lk sgl
-- op in out A out in out len ext pipe
2#0010# => (FPU, OP_FPOP, FRA, FRB, NONE, FRT, '0', '0', '0', '0', ZERO, '0', NONE, '0', '0', '0', '0', '0', '0', RC, '0', '0'), -- fdiv
2#0100# => (FPU, OP_FPOP, FRA, FRB, NONE, FRT, '0', '0', '0', '0', ZERO, '0', NONE, '0', '0', '0', '0', '0', '0', RC, '0', '0'), -- fsub
2#0101# => (FPU, OP_FPOP, FRA, FRB, NONE, FRT, '0', '0', '0', '0', ZERO, '0', NONE, '0', '0', '0', '0', '0', '0', RC, '0', '0'), -- fadd
2#1001# => (FPU, OP_FPOP, FRA, NONE, FRC, FRT, '0', '0', '0', '0', ZERO, '0', NONE, '0', '0', '0', '0', '0', '0', RC, '0', '0'), -- fmul

292
fpu.vhdl
Unescape Escape View File

@ -40,10 +40,12 @@ architecture behaviour of fpu is
DO_FMR, DO_FMRG,
DO_FCFID, DO_FCTI,
DO_FRSP, DO_FRI,
DO_FADD, DO_FMUL,
DO_FADD, DO_FMUL, DO_FDIV,
FRI_1,
ADD_SHIFT, ADD_2, ADD_3,
MULT_1,
LOOKUP,
DIV_2, DIV_3, DIV_4, DIV_5, DIV_6,
INT_SHIFT, INT_ROUND, INT_ISHIFT,
INT_FINAL, INT_CHECK, INT_OFLOW,
FINISH, NORMALIZE,
@ -51,6 +53,7 @@ architecture behaviour of fpu is
ROUNDING, ROUNDING_2, ROUNDING_3,
DENORM,
RENORM_A, RENORM_A2,
RENORM_B, RENORM_B2,
RENORM_C, RENORM_C2);

type reg_type is record
@ -72,6 +75,7 @@ architecture behaviour of fpu is
r : std_ulogic_vector(63 downto 0); -- 10.54 format
x : std_ulogic;
p : std_ulogic_vector(63 downto 0); -- 8.56 format
y : std_ulogic_vector(63 downto 0); -- 8.56 format
result_sign : std_ulogic;
result_class : fp_number_class;
result_exp : signed(EXP_BITS-1 downto 0);
@ -91,8 +95,11 @@ architecture behaviour of fpu is
add_bsmall : std_ulogic;
is_multiply : std_ulogic;
first : std_ulogic;
count : unsigned(1 downto 0);
end record;

type lookup_table is array(0 to 255) of std_ulogic_vector(17 downto 0);

signal r, rin : reg_type;

signal fp_result : std_ulogic_vector(63 downto 0);
@ -114,7 +121,9 @@ architecture behaviour of fpu is
signal multiply_to_f : MultiplyOutputType;
signal msel_1 : std_ulogic_vector(1 downto 0);
signal msel_2 : std_ulogic_vector(1 downto 0);
signal msel_add : std_ulogic_vector(1 downto 0);
signal msel_inv : std_ulogic;
signal inverse_est : std_ulogic_vector(18 downto 0);

-- opsel values
constant AIN_R : std_ulogic_vector(1 downto 0) := "00";
@ -134,11 +143,61 @@ architecture behaviour of fpu is
-- msel values
constant MUL1_A : std_ulogic_vector(1 downto 0) := "00";
constant MUL1_B : std_ulogic_vector(1 downto 0) := "01";
constant MUL1_Y : std_ulogic_vector(1 downto 0) := "10";
constant MUL1_R : std_ulogic_vector(1 downto 0) := "11";

constant MUL2_C : std_ulogic_vector(1 downto 0) := "00";
constant MUL2_LUT : std_ulogic_vector(1 downto 0) := "01";
constant MUL2_P : std_ulogic_vector(1 downto 0) := "10";
constant MUL2_R : std_ulogic_vector(1 downto 0) := "11";

constant MULADD_ZERO : std_ulogic_vector(1 downto 0) := "00";
constant MULADD_CONST : std_ulogic_vector(1 downto 0) := "01";
constant MULADD_A : std_ulogic_vector(1 downto 0) := "10";

-- Inverse lookup table, indexed by the top 8 fraction bits
-- Output range is [0.5, 1) in 0.19 format, though the top
-- bit isn't stored since it is always 1.
-- Each output value is the inverse of the center of the input
-- range for the value, i.e. entry 0 is 1 / (1 + 1/512),
-- entry 1 is 1 / (1 + 3/512), etc.
signal inverse_table : lookup_table := (
-- 1/x lookup table
-- Unit bit is assumed to be 1, so input range is [1, 2)
18x"3fc01", 18x"3f411", 18x"3ec31", 18x"3e460", 18x"3dc9f", 18x"3d4ec", 18x"3cd49", 18x"3c5b5",
18x"3be2f", 18x"3b6b8", 18x"3af4f", 18x"3a7f4", 18x"3a0a7", 18x"39968", 18x"39237", 18x"38b14",
18x"383fe", 18x"37cf5", 18x"375f9", 18x"36f0a", 18x"36828", 18x"36153", 18x"35a8a", 18x"353ce",
18x"34d1e", 18x"3467a", 18x"33fe3", 18x"33957", 18x"332d7", 18x"32c62", 18x"325f9", 18x"31f9c",
18x"3194a", 18x"31303", 18x"30cc7", 18x"30696", 18x"30070", 18x"2fa54", 18x"2f443", 18x"2ee3d",
18x"2e841", 18x"2e250", 18x"2dc68", 18x"2d68b", 18x"2d0b8", 18x"2caee", 18x"2c52e", 18x"2bf79",
18x"2b9cc", 18x"2b429", 18x"2ae90", 18x"2a900", 18x"2a379", 18x"29dfb", 18x"29887", 18x"2931b",
18x"28db8", 18x"2885e", 18x"2830d", 18x"27dc4", 18x"27884", 18x"2734d", 18x"26e1d", 18x"268f6",
18x"263d8", 18x"25ec1", 18x"259b3", 18x"254ac", 18x"24fad", 18x"24ab7", 18x"245c8", 18x"240e1",
18x"23c01", 18x"23729", 18x"23259", 18x"22d90", 18x"228ce", 18x"22413", 18x"21f60", 18x"21ab4",
18x"2160f", 18x"21172", 18x"20cdb", 18x"2084b", 18x"203c2", 18x"1ff40", 18x"1fac4", 18x"1f64f",
18x"1f1e1", 18x"1ed79", 18x"1e918", 18x"1e4be", 18x"1e069", 18x"1dc1b", 18x"1d7d4", 18x"1d392",
18x"1cf57", 18x"1cb22", 18x"1c6f3", 18x"1c2ca", 18x"1bea7", 18x"1ba8a", 18x"1b672", 18x"1b261",
18x"1ae55", 18x"1aa50", 18x"1a64f", 18x"1a255", 18x"19e60", 18x"19a70", 18x"19686", 18x"192a2",
18x"18ec3", 18x"18ae9", 18x"18715", 18x"18345", 18x"17f7c", 18x"17bb7", 18x"177f7", 18x"1743d",
18x"17087", 18x"16cd7", 18x"1692c", 18x"16585", 18x"161e4", 18x"15e47", 18x"15ab0", 18x"1571d",
18x"1538e", 18x"15005", 18x"14c80", 18x"14900", 18x"14584", 18x"1420d", 18x"13e9b", 18x"13b2d",
18x"137c3", 18x"1345e", 18x"130fe", 18x"12da2", 18x"12a4a", 18x"126f6", 18x"123a7", 18x"1205c",
18x"11d15", 18x"119d2", 18x"11694", 18x"11359", 18x"11023", 18x"10cf1", 18x"109c2", 18x"10698",
18x"10372", 18x"10050", 18x"0fd31", 18x"0fa17", 18x"0f700", 18x"0f3ed", 18x"0f0de", 18x"0edd3",
18x"0eacb", 18x"0e7c7", 18x"0e4c7", 18x"0e1ca", 18x"0ded2", 18x"0dbdc", 18x"0d8eb", 18x"0d5fc",
18x"0d312", 18x"0d02b", 18x"0cd47", 18x"0ca67", 18x"0c78a", 18x"0c4b1", 18x"0c1db", 18x"0bf09",
18x"0bc3a", 18x"0b96e", 18x"0b6a5", 18x"0b3e0", 18x"0b11e", 18x"0ae5f", 18x"0aba3", 18x"0a8eb",
18x"0a636", 18x"0a383", 18x"0a0d4", 18x"09e28", 18x"09b80", 18x"098da", 18x"09637", 18x"09397",
18x"090fb", 18x"08e61", 18x"08bca", 18x"08936", 18x"086a5", 18x"08417", 18x"0818c", 18x"07f04",
18x"07c7e", 18x"079fc", 18x"0777c", 18x"074ff", 18x"07284", 18x"0700d", 18x"06d98", 18x"06b26",
18x"068b6", 18x"0664a", 18x"063e0", 18x"06178", 18x"05f13", 18x"05cb1", 18x"05a52", 18x"057f5",
18x"0559a", 18x"05342", 18x"050ed", 18x"04e9a", 18x"04c4a", 18x"049fc", 18x"047b0", 18x"04567",
18x"04321", 18x"040dd", 18x"03e9b", 18x"03c5c", 18x"03a1f", 18x"037e4", 18x"035ac", 18x"03376",
18x"03142", 18x"02f11", 18x"02ce2", 18x"02ab5", 18x"0288b", 18x"02663", 18x"0243d", 18x"02219",
18x"01ff7", 18x"01dd8", 18x"01bbb", 18x"019a0", 18x"01787", 18x"01570", 18x"0135b", 18x"01149",
18x"00f39", 18x"00d2a", 18x"00b1e", 18x"00914", 18x"0070c", 18x"00506", 18x"00302", 18x"00100"
);

-- Left and right shifter with 120 bit input and 64 bit output.
-- Shifts inp left by shift bits and returns the upper 64 bits of
-- the result. The shift parameter is interpreted as a signed
@ -359,6 +418,14 @@ begin
end if;
end process;

-- synchronous reads from lookup table
lut_access: process(clk)
begin
if rising_edge(clk) then
inverse_est <= '1' & inverse_table(to_integer(unsigned(r.b.mantissa(53 downto 46))));
end if;
end process;

e_out.busy <= r.busy;
e_out.exception <= r.fpscr(FPSCR_FEX);
e_out.interrupt <= r.do_intr;
@ -391,6 +458,7 @@ begin
variable update_fx : std_ulogic;
variable arith_done : std_ulogic;
variable invalid : std_ulogic;
variable zero_divide : std_ulogic;
variable mant_nz : std_ulogic;
variable min_exp : signed(EXP_BITS-1 downto 0);
variable max_exp : signed(EXP_BITS-1 downto 0);
@ -408,9 +476,14 @@ begin
variable qnan_result : std_ulogic;
variable longmask : std_ulogic;
variable set_a : std_ulogic;
variable set_b : std_ulogic;
variable set_c : std_ulogic;
variable px_nz : std_ulogic;
variable maddend : std_ulogic_vector(127 downto 0);
variable set_y : std_ulogic;
variable pcmpb_eq : std_ulogic;
variable pcmpb_lt : std_ulogic;
variable pshift : std_ulogic;
begin
v := r;
illegal := '0';
@ -478,8 +551,16 @@ begin
exp_huge := '1';
end if;

-- Compare P with zero
-- Compare P with zero and with B
px_nz := or (r.p(57 downto 4));
pcmpb_eq := '0';
if r.p(59 downto 4) = r.b.mantissa(55 downto 0) then
pcmpb_eq := '1';
end if;
pcmpb_lt := '0';
if unsigned(r.p(59 downto 4)) < unsigned(r.b.mantissa(55 downto 0)) then
pcmpb_lt := '1';
end if;

v.writing_back := '0';
v.instr_done := '0';
@ -498,18 +579,22 @@ begin
update_fx := '0';
arith_done := '0';
invalid := '0';
zero_divide := '0';
renormalize := '0';
set_x := '0';
qnan_result := '0';
longmask := r.single_prec;
set_a := '0';
set_b := '0';
set_c := '0';
f_to_multiply.is_32bit <= '0';
f_to_multiply.valid <= '0';
msel_1 <= MUL1_A;
msel_2 <= MUL2_C;
msel_add <= MULADD_ZERO;
msel_inv <= '0';

set_y := '0';
pshift := '0';
case r.state is
when IDLE =>
if e_in.valid = '1' then
@ -550,6 +635,8 @@ begin
when "01111" =>
v.round_mode := "001";
v.state := DO_FCTI;
when "10010" =>
v.state := DO_FDIV;
when "10100" | "10101" =>
v.state := DO_FADD;
when "11001" =>
@ -897,6 +984,63 @@ begin
arith_done := '1';
end if;

when DO_FDIV =>
opsel_a <= AIN_A;
v.result_sign := r.a.negative;
v.result_class := r.a.class;
v.result_exp := r.a.exponent;
v.fpscr(FPSCR_FR) := '0';
v.fpscr(FPSCR_FI) := '0';
v.result_sign := r.a.negative xor r.b.negative;
v.result_exp := r.a.exponent - r.b.exponent;
v.count := "00";
if r.a.class = FINITE and r.b.class = FINITE then
-- Renormalize denorm operands
if r.a.mantissa(54) = '0' then
v.state := RENORM_A;
elsif r.b.mantissa(54) = '0' then
opsel_a <= AIN_B;
v.state := RENORM_B;
else
v.first := '1';
v.state := DIV_2;
end if;
else
if (r.a.class = NAN and r.a.mantissa(53) = '0') or
(r.b.class = NAN and r.b.mantissa(53) = '0') then
-- Signalling NAN
v.fpscr(FPSCR_VXSNAN) := '1';
invalid := '1';
end if;
if r.a.class = NAN then
-- result is A
v.result_sign := r.a.negative;
elsif r.b.class = NAN then
v.result_class := NAN;
v.result_sign := r.b.negative;
opsel_a <= AIN_B;
elsif r.b.class = INFINITY then
if r.a.class = INFINITY then
v.fpscr(FPSCR_VXIDI) := '1';
qnan_result := '1';
else
v.result_class := ZERO;
end if;
elsif r.b.class = ZERO then
if r.a.class = ZERO then
v.fpscr(FPSCR_VXZDZ) := '1';
qnan_result := '1';
else
if r.a.class = FINITE then
zero_divide := '1';
end if;
v.result_class := INFINITY;
end if;
-- else r.b.class = FINITE, result_class = r.a.class
end if;
arith_done := '1';
end if;

when RENORM_A =>
renormalize := '1';
v.state := RENORM_A2;
@ -904,14 +1048,33 @@ begin
when RENORM_A2 =>
set_a := '1';
v.result_exp := new_exp;
opsel_a <= AIN_C;
if r.c.mantissa(54) = '1' then
v.first := '1';
v.state := MULT_1;
if r.insn(4) = '1' then
opsel_a <= AIN_C;
if r.c.mantissa(54) = '1' then
v.first := '1';
v.state := MULT_1;
else
v.state := RENORM_C;
end if;
else
v.state := RENORM_C;
opsel_a <= AIN_B;
if r.b.mantissa(54) = '1' then
v.first := '1';
v.state := DIV_2;
else
v.state := RENORM_B;
end if;
end if;

when RENORM_B =>
renormalize := '1';
v.state := RENORM_B2;

when RENORM_B2 =>
set_b := '1';
v.result_exp := r.result_exp + r.shift;
v.state := LOOKUP;

when RENORM_C =>
renormalize := '1';
v.state := RENORM_C2;
@ -982,6 +1145,82 @@ begin
v.state := FINISH;
end if;

when LOOKUP =>
opsel_a <= AIN_B;
-- wait one cycle for inverse_table[B] lookup
v.first := '1';
v.state := DIV_2;

when DIV_2 =>
-- compute Y = inverse_table[B] (when count=0); P = 2 - B * Y
msel_1 <= MUL1_B;
msel_add <= MULADD_CONST;
msel_inv <= '1';
if r.count = 0 then
msel_2 <= MUL2_LUT;
else
msel_2 <= MUL2_P;
end if;
set_y := r.first;
pshift := '1';
f_to_multiply.valid <= r.first;
if multiply_to_f.valid = '1' then
v.first := '1';
v.count := r.count + 1;
v.state := DIV_3;
end if;

when DIV_3 =>
-- compute Y = P = P * Y
msel_1 <= MUL1_Y;
msel_2 <= MUL2_P;
f_to_multiply.valid <= r.first;
pshift := '1';
if multiply_to_f.valid = '1' then
v.first := '1';
if r.count = 3 then
v.state := DIV_4;
else
v.state := DIV_2;
end if;
end if;

when DIV_4 =>
-- compute R = P = A * Y (quotient)
msel_1 <= MUL1_A;
msel_2 <= MUL2_P;
set_y := r.first;
f_to_multiply.valid <= r.first;
pshift := '1';
if multiply_to_f.valid = '1' then
opsel_r <= RES_MULT;
v.first := '1';
v.state := DIV_5;
end if;

when DIV_5 =>
-- compute P = A - B * R (remainder)
msel_1 <= MUL1_B;
msel_2 <= MUL2_R;
msel_add <= MULADD_A;
msel_inv <= '1';
f_to_multiply.valid <= r.first;
if multiply_to_f.valid = '1' then
v.state := DIV_6;
end if;

when DIV_6 =>
-- test if remainder is 0 or >= B
if pcmpb_lt = '1' then
-- quotient is correct, set X if remainder non-zero
v.x := r.p(58) or px_nz;
else
-- quotient needs to be incremented by 1
carry_in <= '1';
v.x := not pcmpb_eq;
end if;
v.state := FINISH;

when INT_SHIFT =>
opsel_r <= RES_SHIFT;
set_x := '1';
@ -1218,6 +1457,9 @@ begin

end case;

if zero_divide = '1' then
v.fpscr(FPSCR_ZX) := '1';
end if;
if qnan_result = '1' then
invalid := '1';
v.result_class := NAN;
@ -1227,7 +1469,9 @@ begin
end if;
if arith_done = '1' then
-- Enabled invalid exception doesn't write result or FPRF
if (invalid and r.fpscr(FPSCR_VE)) = '0' then
-- Neither does enabled zero-divide exception
if (invalid and r.fpscr(FPSCR_VE)) = '0' and
(zero_divide and r.fpscr(FPSCR_ZE)) = '0' then
v.writing_back := '1';
v.update_fprf := '1';
end if;
@ -1236,30 +1480,52 @@ begin
update_fx := '1';
end if;

-- Multiplier data path
-- Multiplier and divide/square root data path
case msel_1 is
when MUL1_A =>
f_to_multiply.data1 <= r.a.mantissa(61 downto 0) & "00";
when MUL1_B =>
f_to_multiply.data1 <= r.b.mantissa(61 downto 0) & "00";
when MUL1_Y =>
f_to_multiply.data1 <= r.y;
when others =>
f_to_multiply.data1 <= r.r(61 downto 0) & "00";
end case;
case msel_2 is
when MUL2_C =>
f_to_multiply.data2 <= r.c.mantissa(61 downto 0) & "00";
when MUL2_LUT =>
f_to_multiply.data2 <= x"00" & inverse_est & '0' & x"000000000";
when MUL2_P =>
f_to_multiply.data2 <= r.p;
when others =>
f_to_multiply.data2 <= r.r(61 downto 0) & "00";
end case;
maddend := (others => '0');
case msel_add is
when MULADD_CONST =>
-- addend is 2.0 in 16.112 format
maddend(113) := '1'; -- 2.0
when MULADD_A =>
-- addend is A in 16.112 format
maddend(121 downto 58) := r.a.mantissa;
when others =>
end case;
if msel_inv = '1' then
f_to_multiply.addend <= not maddend;
else
f_to_multiply.addend <= maddend;
end if;
f_to_multiply.not_result <= msel_inv;
if set_y = '1' then
v.y := f_to_multiply.data2;
end if;
if multiply_to_f.valid = '1' then
v.p := multiply_to_f.result(63 downto 0);
if pshift = '0' then
v.p := multiply_to_f.result(63 downto 0);
else
v.p := multiply_to_f.result(119 downto 56);
end if;
end if;

-- Data path.
@ -1378,6 +1644,10 @@ begin
v.a.exponent := new_exp;
v.a.mantissa := shift_res;
end if;
if set_b = '1' then
v.b.exponent := new_exp;
v.b.mantissa := shift_res;
end if;
if set_c = '1' then
v.c.exponent := new_exp;
v.c.mantissa := shift_res;

39
tests/fpu/fpu.c
Unescape Escape View File

@ -1007,6 +1007,7 @@ struct mulvals {
{ 0xbff0000000000000, 0x3ff0000000000000, 0xbff0000000000000 },
{ 0xbf4fff801fffffff, 0x6d7fffff8000007f, 0xecdfff7fa001fffe },
{ 0x3fbd50275a65ed80, 0x0010000000000000, 0x0001d50275a65ed8 },
{ 0x3fe95d8937acf1ce, 0x0000000000000001, 0x0000000000000001 },
};

int test15(long arg)
@ -1073,6 +1074,43 @@ int fpu_test_16(void)
return trapit(0, test16);
}

struct divvals {
unsigned long val_a;
unsigned long val_b;
unsigned long prod;
} divvals[] = {
{ 0x3ff0000000000000, 0x0000000000000000, 0x7ff0000000000000 },
{ 0x3ff0000000000000, 0x3ff0000000000000, 0x3ff0000000000000 },
{ 0xbff0000000000000, 0x3ff0000000000000, 0xbff0000000000000 },
{ 0x4000000000000000, 0x4008000000000000, 0x3fe5555555555555 },
{ 0xc01fff0007ffffff, 0xc03ffffffdffffbf, 0x3fcfff0009fff041 },
};

int test17(long arg)
{
long i;
unsigned long result;
struct divvals *vp = divvals;

set_fpscr(FPS_RN_NEAR);
for (i = 0; i < sizeof(divvals) / sizeof(divvals[0]); ++i, ++vp) {
asm("lfd 5,0(%0); lfd 6,8(%0); fdiv 7,5,6; stfd 7,0(%1)"
: : "b" (&vp->val_a), "b" (&result) : "memory");
if (result != vp->prod) {
print_hex(i, 2, " ");
print_hex(result, 16, " ");
return i + 1;
}
}
return 0;
}

int fpu_test_17(void)
{
enable_fp();
return trapit(0, test17);
}

int fail = 0;

void do_test(int num, int (*test)(void))
@ -1114,6 +1152,7 @@ int main(void)
do_test(14, fpu_test_14);
do_test(15, fpu_test_15);
do_test(16, fpu_test_16);
do_test(17, fpu_test_17);

return fail;
}

BIN
tests/test_fpu.bin
View File

Binary file not shown.

1
tests/test_fpu.console_out
Unescape Escape View File

@ -14,3 +14,4 @@ test 13:PASS
test 14:PASS
test 15:PASS
test 16:PASS
test 17:PASS

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