target/riscv: Generalize gen_nanbox_fpr to gen_nanbox_s

Do not depend on the RVD extension, take input and output via
TCGv_i64 instead of fpu regno. Move the function to translate.c
so that it can be used in multiple trans_*.inc.c files.

Backports d36a86d01e67792c51dd2a82360cda012bde9442
This commit is contained in:
Richard Henderson 2021-03-08 12:24:18 -05:00 committed by Lioncash
parent adb4d9907a
commit 52f2d5cbee
2 changed files with 13 additions and 17 deletions

View file

@ -23,22 +23,6 @@
return false; \
} while (0)
/*
* RISC-V requires NaN-boxing of narrower width floating
* point values. This applies when a 32-bit value is
* assigned to a 64-bit FP register. Thus this does not
* apply when the RVD extension is not present.
*/
static void gen_nanbox_fpr(DisasContext *ctx, int regno)
{
TCGContext *tcg_ctx = ctx->uc->tcg_ctx;
if (has_ext(ctx, RVD)) {
tcg_gen_ori_i64(tcg_ctx, tcg_ctx->cpu_fpr_risc[regno], tcg_ctx->cpu_fpr_risc[regno],
MAKE_64BIT_MASK(32, 32));
}
}
static bool trans_flw(DisasContext *ctx, arg_flw *a)
{
TCGContext *tcg_ctx = ctx->uc->tcg_ctx;
@ -49,7 +33,7 @@ static bool trans_flw(DisasContext *ctx, arg_flw *a)
tcg_gen_addi_tl(tcg_ctx, t0, t0, a->imm);
tcg_gen_qemu_ld_i64(ctx->uc, tcg_ctx->cpu_fpr_risc[a->rd], t0, ctx->mem_idx, MO_TEUL);
gen_nanbox_fpr(ctx, a->rd);
gen_nanbox_s(ctx, tcg_ctx->cpu_fpr_risc[a->rd], tcg_ctx->cpu_fpr_risc[a->rd]);
tcg_temp_free(tcg_ctx, t0);
mark_fs_dirty(ctx);

View file

@ -93,6 +93,18 @@ static inline bool has_ext(DisasContext *ctx, uint32_t ext)
return ctx->misa & ext;
}
/*
* RISC-V requires NaN-boxing of narrower width floating point values.
* This applies when a 32-bit value is assigned to a 64-bit FP register.
* For consistency and simplicity, we nanbox results even when the RVD
* extension is not present.
*/
static void gen_nanbox_s(DisasContext *s, TCGv_i64 out, TCGv_i64 in)
{
TCGContext *tcg_ctx = s->uc->tcg_ctx;
tcg_gen_ori_i64(tcg_ctx, out, in, MAKE_64BIT_MASK(32, 32));
}
static void generate_exception(DisasContext *ctx, int excp)
{
TCGContext *tcg_ctx = ctx->uc->tcg_ctx;