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powerpc/85xx: Fix SPE float to integer conversion failure

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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>
This commit is contained in:
Shan Hai 2010-11-17 10:28:53 +08:00 committed by Kumar Gala
parent cf773702b9
commit afc0a07d4a
1 changed files with 8 additions and 4 deletions
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12
arch/powerpc/math-emu/math_efp.c
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@ -322,7 +322,8 @@ int do_spe_mathemu(struct pt_regs *regs)
} 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 @@ cmp_s:
} 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 @@ cmp_d:
_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: