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target/arm: Handle FPCR.NEP for BFCVT scalar

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Currently we implement BFCVT scalar via do_fp1_scalar().  This works
even though BFCVT is a narrowing operation from 32 to 16 bits,
because we can use write_fp_sreg() for float16. However, FPCR.NEP
support requires that we use write_fp_hreg_merging() for float16
outputs, so we can't continue to borrow the non-narrowing
do_fp1_scalar() function for this. Split out trans_BFCVT_s()
into its own implementation that honours FPCR.NEP.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
This commit is contained in:
Peter Maydell 2025-02-01 16:39:21 +00:00
parent 0378199dc2
commit 053b39aad9
1 changed files with 21 additions and 4 deletions
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25
target/arm/tcg/translate-a64.c
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@ -8571,10 +8571,27 @@ static const FPScalar1 f_scalar_frintx = {
};
TRANS(FRINTX_s, do_fp1_scalar, a, &f_scalar_frintx, -1)
static const FPScalar1 f_scalar_bfcvt = {
.gen_s = gen_helper_bfcvt,
};
TRANS_FEAT(BFCVT_s, aa64_bf16, do_fp1_scalar_ah, a, &f_scalar_bfcvt, -1)
static bool trans_BFCVT_s(DisasContext *s, arg_rr_e *a)
{
ARMFPStatusFlavour fpsttype = s->fpcr_ah ? FPST_AH : FPST_A64;
TCGv_i32 t32;
int check;
if (!dc_isar_feature(aa64_bf16, s)) {
return false;
}
check = fp_access_check_scalar_hsd(s, a->esz);
if (check <= 0) {
return check == 0;
}
t32 = read_fp_sreg(s, a->rn);
gen_helper_bfcvt(t32, t32, fpstatus_ptr(fpsttype));
write_fp_hreg_merging(s, a->rd, a->rd, t32);
return true;
}
static const FPScalar1 f_scalar_frint32 = {
NULL,