From 93262b1625ecb9c6ff22d5a51f38e312b5b7725a Mon Sep 17 00:00:00 2001 From: Peter Maydell Date: Mon, 18 Apr 2011 19:07:11 +0100 Subject: [PATCH] target-arm: Handle UNDEFs for Neon single element load/stores Handle the UNDEF and UNPREDICTABLE cases for Neon "single element to one lane" VLD and "single element from one lane" VST. Signed-off-by: Peter Maydell Signed-off-by: Aurelien Jarno --- target-arm/translate.c | 34 ++++++++++++++++++++++++++++++++++ 1 file changed, 34 insertions(+) diff --git a/target-arm/translate.c b/target-arm/translate.c index e1bda57e81..80b25ac5c4 100644 --- a/target-arm/translate.c +++ b/target-arm/translate.c @@ -3975,6 +3975,7 @@ static int disas_neon_ls_insn(CPUState * env, DisasContext *s, uint32_t insn) stride = (1 << size) * nregs; } else { /* Single element. */ + int idx = (insn >> 4) & 0xf; pass = (insn >> 7) & 1; switch (size) { case 0: @@ -3993,6 +3994,39 @@ static int disas_neon_ls_insn(CPUState * env, DisasContext *s, uint32_t insn) abort(); } nregs = ((insn >> 8) & 3) + 1; + /* Catch the UNDEF cases. This is unavoidably a bit messy. */ + switch (nregs) { + case 1: + if (((idx & (1 << size)) != 0) || + (size == 2 && ((idx & 3) == 1 || (idx & 3) == 2))) { + return 1; + } + break; + case 3: + if ((idx & 1) != 0) { + return 1; + } + /* fall through */ + case 2: + if (size == 2 && (idx & 2) != 0) { + return 1; + } + break; + case 4: + if ((size == 2) && ((idx & 3) == 3)) { + return 1; + } + break; + default: + abort(); + } + if ((rd + stride * (nregs - 1)) > 31) { + /* Attempts to write off the end of the register file + * are UNPREDICTABLE; we choose to UNDEF because otherwise + * the neon_load_reg() would write off the end of the array. + */ + return 1; + } addr = tcg_temp_new_i32(); load_reg_var(s, addr, rn); for (reg = 0; reg < nregs; reg++) {