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Re: [Qemu-devel] [PATCH 06/10] target-mips: add microMIPS ASE support
From: |
Richard Henderson |
Subject: |
Re: [Qemu-devel] [PATCH 06/10] target-mips: add microMIPS ASE support |
Date: |
Fri, 04 Jun 2010 11:30:38 -0700 |
User-agent: |
Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.1.9) Gecko/20100430 Fedora/3.0.4-3.fc13 Thunderbird/3.0.4 |
On 05/24/2010 09:19 AM, Nathan Froyd wrote:
> + int (*ldfun)(target_ulong);
> +
> + switch (mem_idx)
> + {
> + case 0: ldfun = ldl_kernel; break;
> + case 1: ldfun = ldl_super; break;
> + default:
> + case 2: ldfun = ldl_user; break;
> + }
This *should* now be a compile error. The return type should
now be "uint32_t", not "int".
> + env->active_tc.gpr[multiple_regs[i]] = ldfun(addr);
...
> + env->active_tc.gpr[31] = ldfun(addr);
Which means these will need explicit sign-extensions.
> + void (*stfun)(target_ulong, int);
Similarly "uint32_t", though no other changes should be required.
> @@ -2535,26 +2555,29 @@ static void gen_compute_branch (DisasContext *ctx,
> uint32_t opc,
> case OPC_JALX:
> ctx->hflags |= MIPS_HFLAG_BX;
> /* Fallthrough */
> + case OPC_JALS:
> case OPC_JAL:
> blink = 31;
> ctx->hflags |= MIPS_HFLAG_B;
> - ctx->hflags |= (ctx->hflags & MIPS_HFLAG_M16
> + ctx->hflags |= (opc == OPC_JALS
> ? MIPS_HFLAG_BDS16
> : MIPS_HFLAG_BDS32);
Changed semantics here? You're no longer testing M16 bit.
Or is that later handled by switching mips16 to JALS too?
> @@ -8678,7 +8709,7 @@ static int decode_mips16_opc (CPUState *env,
> DisasContext *ctx,
> int ra = (ctx->opcode >> 5) & 0x1;
>
> if (link) {
> - op = nd ? OPC_JALRC : OPC_JALR;
> + op = nd ? OPC_JALRC : OPC_JALRS;
Here's one conversion of mips16 to the new "S" opcodes, but
this is the only one. It *seems* like there should be more.
And if so, perhaps this patch should be broken into two, where
you introduce the new opcodes and hflags changes and apply them
as-needed to the mips16 code. Thus one can verify that the
semantics for mips16 are the same before and after.
... Unless there's some micromips dependency I'm not seeing?
> + if (base == 0) {
> + tcg_gen_movi_tl(t0, 0);
> + } else {
> + gen_load_gpr(t0, base);
> + }
gen_load_gpr already takes care of R0.
> +#if 0
> + case 0x01:
> + switch (minor) {
> + case MFHI_ACC:
> + gen_HILO(ctx, OPC_MFHI, rs);
New if 0 code?
r~
- Re: [Qemu-devel] [PATCH 06/10] target-mips: add microMIPS ASE support,
Richard Henderson <=