powerpc/85xx: Fix SPE float to integer conversion failure
Conversion from float to integer should based on both the instruction
encoding and the sign of the operand.
A simple testcase to show the issue:
static float fm;
static signed int si_min = (-2147483647 - 1);
static unsigned int ui;
int main()
{
fm = (float) si_min; ;
ui = (unsigned int)fm;
printf("ui=%d, should be %d\n", ui, si_min);
return 0;
}
Result: ui=-1, should be -2147483648
Signed-off-by: Shan Hai <shan.hai@windriver.com>
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
diff --git a/arch/powerpc/math-emu/math_efp.c b/arch/powerpc/math-emu/math_efp.c
index 634830b..6227920 100644
--- a/arch/powerpc/math-emu/math_efp.c
+++ b/arch/powerpc/math-emu/math_efp.c
@@ -322,7 +322,8 @@
} else {
_FP_ROUND_ZERO(1, SB);
}
- FP_TO_INT_S(vc.wp[1], SB, 32, ((func & 0x3) != 0));
+ FP_TO_INT_S(vc.wp[1], SB, 32,
+ (((func & 0x3) != 0) || SB_s));
goto update_regs;
default:
@@ -460,7 +461,8 @@
} else {
_FP_ROUND_ZERO(2, DB);
}
- FP_TO_INT_D(vc.wp[1], DB, 32, ((func & 0x3) != 0));
+ FP_TO_INT_D(vc.wp[1], DB, 32,
+ (((func & 0x3) != 0) || DB_s));
goto update_regs;
default:
@@ -591,8 +593,10 @@
_FP_ROUND_ZERO(1, SB0);
_FP_ROUND_ZERO(1, SB1);
}
- FP_TO_INT_S(vc.wp[0], SB0, 32, ((func & 0x3) != 0));
- FP_TO_INT_S(vc.wp[1], SB1, 32, ((func & 0x3) != 0));
+ FP_TO_INT_S(vc.wp[0], SB0, 32,
+ (((func & 0x3) != 0) || SB0_s));
+ FP_TO_INT_S(vc.wp[1], SB1, 32,
+ (((func & 0x3) != 0) || SB1_s));
goto update_regs;
default: