yuzu/unicorn
1
0
Fork 0
mirror of https://github.com/yuzu-emu/unicorn.git synced 2025-01-22 11:31:00 +00:00
Code Issues Packages Projects Releases Wiki Activity

target/i386: fix fbstp handling of negative zero

Browse source 
The fbstp implementation stores +0 when the rounded result should be
-0 because it compares an integer value with 0 to determine the sign.
Fix this by checking the sign bit of the operand instead.

Backports commit 18c53e1e73197a24f9f4b66b1276eb9868db5bf0 from qemu
This commit is contained in:
Joseph Myers 2020-06-15 13:08:36 -04:00 committed by Lioncash
parent c796ee5e13
commit 477a0af161
1 changed files with 4 additions and 1 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

5
qemu/target/i386/fpu_helper.c
View file

@ -692,11 +692,14 @@ void helper_fbst_ST0(CPUX86State *env, target_ulong ptr)
int v; int v;
target_ulong mem_ref, mem_end; target_ulong mem_ref, mem_end;
int64_t val; int64_t val;
CPU_LDoubleU temp;
temp.d = ST0;
val = floatx80_to_int64(ST0, &env->fp_status); val = floatx80_to_int64(ST0, &env->fp_status);
mem_ref = ptr; mem_ref = ptr;
mem_end = mem_ref + 9; mem_end = mem_ref + 9;
if (val < 0) { if (SIGND(temp)) {
cpu_stb_data_ra(env, mem_end, 0x80, GETPC()); cpu_stb_data_ra(env, mem_end, 0x80, GETPC());
val = -val; val = -val;
} else { } else {