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| From: | Tom Musta |
| Subject: | Re: [Qemu-devel] [PATCH 03/19] General Support for VSX Helpers |
| Date: | Thu, 24 Oct 2013 15:42:19 -0500 |
| User-agent: | Mozilla/5.0 (Windows NT 6.1; WOW64; rv:24.0) Gecko/20100101 Thunderbird/24.0.1 |
On 10/24/2013 1:51 PM, Richard Henderson wrote:
On 10/24/2013 09:19 AM, Tom Musta wrote:+#define GEN_VSX_HELPER_2(name, op1, op2, inval, type) \ +static void gen_##name(DisasContext * ctx) \ +{ \ + TCGv_i32 opc; \ + if (unlikely(!ctx->vsx_enabled)) { \ + gen_exception(ctx, POWERPC_EXCP_VSXU); \ + return; \ + } \ + /* NIP cannot be restored if the memory exception comes from an helper */ \ + gen_update_nip(ctx, ctx->nip - 4); \ + opc = tcg_const_i32(ctx->opcode); \ + gen_helper_##name(cpu_env, opc); \ + tcg_temp_free_i32(opc); \ +}I'm not a fan of delaying decode to the helpers... You're mostly doing this to avoid passing 3-4 arguments for the register numbers?
Because the VSRs are 128 bits wide and because there is an interesting relationship with the FPRs and AVRs, passing 6 or more arguments would typically be required (2 per VSR). And, they would need to be stitched back together into a single structure in order to use the loops in the vector routines. I did prototype something like this and didn't like it. Unless you are suggesting that the decoded VSR index (0..63) be passed to the helper?
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