From 6822abfdf8b382be4fc84066fa1087e5fef81360 Mon Sep 17 00:00:00 2001 From: Peter Maydell Date: Mon, 14 Jun 2021 16:09:17 +0100 Subject: [PATCH] target/arm: Implement MVE WLSTP insn Implement the MVE WLSTP insn; this is like the existing WLS insn, except that it specifies a size value which is used to set FPSCR.LTPSIZE. Signed-off-by: Peter Maydell Reviewed-by: Richard Henderson Message-id: 20210614151007.4545-8-peter.maydell@linaro.org --- target/arm/t32.decode | 8 ++++++-- target/arm/translate.c | 37 ++++++++++++++++++++++++++++++++++++- 2 files changed, 42 insertions(+), 3 deletions(-) diff --git a/target/arm/t32.decode b/target/arm/t32.decode index 087e514e0a..6906829265 100644 --- a/target/arm/t32.decode +++ b/target/arm/t32.decode @@ -672,8 +672,12 @@ BL 1111 0. .......... 11.1 ............ @branch24 %lob_imm 1:10 11:1 !function=times_2 DLS 1111 0 0000 100 rn:4 1110 0000 0000 0001 - WLS 1111 0 0000 100 rn:4 1100 . .......... 1 imm=%lob_imm - LE 1111 0 0000 0 f:1 0 1111 1100 . .......... 1 imm=%lob_imm + WLS 1111 0 0000 100 rn:4 1100 . .......... 1 imm=%lob_imm size=4 + { + LE 1111 0 0000 0 f:1 0 1111 1100 . .......... 1 imm=%lob_imm + # This is WLSTP + WLS 1111 0 0000 0 size:2 rn:4 1100 . .......... 1 imm=%lob_imm + } LCTP 1111 0 0000 000 1111 1110 0000 0000 0001 ] diff --git a/target/arm/translate.c b/target/arm/translate.c index c49561590c..78878e9b19 100644 --- a/target/arm/translate.c +++ b/target/arm/translate.c @@ -8134,7 +8134,11 @@ static bool trans_WLS(DisasContext *s, arg_WLS *a) return false; } if (a->rn == 13 || a->rn == 15) { - /* CONSTRAINED UNPREDICTABLE: we choose to UNDEF */ + /* + * For WLSTP rn == 15 is a related encoding (LE); the + * other cases caught by this condition are all + * CONSTRAINED UNPREDICTABLE: we choose to UNDEF + */ return false; } if (s->condexec_mask) { @@ -8147,10 +8151,41 @@ static bool trans_WLS(DisasContext *s, arg_WLS *a) */ return false; } + if (a->size != 4) { + /* WLSTP */ + if (!dc_isar_feature(aa32_mve, s)) { + return false; + } + /* + * We need to check that the FPU is enabled here, but mustn't + * call vfp_access_check() to do that because we don't want to + * do the lazy state preservation in the "loop count is zero" case. + * Do the check-and-raise-exception by hand. + */ + if (s->fp_excp_el) { + gen_exception_insn(s, s->pc_curr, EXCP_NOCP, + syn_uncategorized(), s->fp_excp_el); + return true; + } + } + nextlabel = gen_new_label(); tcg_gen_brcondi_i32(TCG_COND_EQ, cpu_R[a->rn], 0, nextlabel); tmp = load_reg(s, a->rn); store_reg(s, 14, tmp); + if (a->size != 4) { + /* + * WLSTP: set FPSCR.LTPSIZE. This requires that we do the + * lazy state preservation, new FP context creation, etc, + * that vfp_access_check() does. We know that the actual + * access check will succeed (ie it won't generate code that + * throws an exception) because we did that check by hand earlier. + */ + bool ok = vfp_access_check(s); + assert(ok); + tmp = tcg_const_i32(a->size); + store_cpu_field(tmp, v7m.ltpsize); + } gen_jmp_tb(s, s->base.pc_next, 1); gen_set_label(nextlabel);