From b1031f1ff0af97e45166f98d645707735e8e5e78 Mon Sep 17 00:00:00 2001 From: Mike Frysinger Date: Mon, 24 Jun 2013 02:06:32 +0000 Subject: sim: bfin: note missing parallel handling of SEARCH The SEARCH insn is an oddball when it comes to parallel usage. It places a big limit on what other insns it can run in parallel with, but we don't currently track the amount of state needed to verify this (since no other insn really requires this). Add a note for now in case we get around to it. --- sim/bfin/ChangeLog | 5 +++++ sim/bfin/bfin-sim.c | 13 +++++++++++++ 2 files changed, 18 insertions(+) (limited to 'sim') diff --git a/sim/bfin/ChangeLog b/sim/bfin/ChangeLog index 17a75f138ce..343a891ad7e 100644 --- a/sim/bfin/ChangeLog +++ b/sim/bfin/ChangeLog @@ -1,3 +1,8 @@ +2013-06-23 Mike Frysinger + + * bfin-sim.c (decode_dsp32alu_0): Add note about broken handling of + SEARCH with parallel insns. + 2013-06-23 Mike Frysinger * bfin-sim.c (decode_dsp32shift_0): Make sure HLs is 0 after last diff --git a/sim/bfin/bfin-sim.c b/sim/bfin/bfin-sim.c index 90e09106c5b..484c4800b24 100644 --- a/sim/bfin/bfin-sim.c +++ b/sim/bfin/bfin-sim.c @@ -5148,6 +5148,19 @@ decode_dsp32alu_0 (SIM_CPU *cpu, bu16 iw0, bu16 iw1) TRACE_INSN (cpu, "(R%i, R%i) = SEARCH R%i (%s);", dst1, dst0, src0, searchmodes[aop]); + /* XXX: The parallel version is a bit weird in its limits: + + This instruction can be issued in parallel with the combination of one + 16-bit length load instruction to the P0 register and one 16-bit NOP. + No other instructions can be issued in parallel with the Vector Search + instruction. Note the following legal and illegal forms. + (r1, r0) = search r2 (LT) || r2 = [p0++p3]; // ILLEGAL + (r1, r0) = search r2 (LT) || r2 = [p0++]; // LEGAL + (r1, r0) = search r2 (LT) || r2 = [p0++]; // LEGAL + + Unfortunately, our parallel insn state doesn't (currently) track enough + details to be able to check this. */ + if (dst0 == dst1) illegal_instruction_combination (cpu); -- cgit v1.2.1