Commit 9ea62f57 authored by Peter Maydell's avatar Peter Maydell Committed by Aurelien Jarno
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target-arm: Fix implementation of VRSQRTS

The implementation of the ARM VRSQRTS instruction (which calculates
(3 - op1 * op2) / 2) was missing the division operation. It also
did not handle the special cases of (0,inf) and (inf,0).
Signed-off-by: default avatarPeter Maydell <>
Reviewed-by: default avatarAurelien Jarno <>
Signed-off-by: default avatarAurelien Jarno <>
parent 6f3300ad
......@@ -2612,8 +2612,16 @@ float32 HELPER(recps_f32)(float32 a, float32 b, CPUState *env)
float32 HELPER(rsqrts_f32)(float32 a, float32 b, CPUState *env)
float_status *s = &env->vfp.fp_status;
float32 two = int32_to_float32(2, s);
float32 three = int32_to_float32(3, s);
return float32_sub(three, float32_mul(a, b, s), s);
float32 product;
if ((float32_is_infinity(a) && float32_is_zero_or_denormal(b)) ||
(float32_is_infinity(b) && float32_is_zero_or_denormal(a))) {
product = float32_zero;
} else {
product = float32_mul(a, b, s);
return float32_div(float32_sub(three, product, s), two, s);
/* NEON helpers. */
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