MIPS: Optimize uasm insn lookup.

Instead of doing a linear search through the insn_table for each
instruction, use the opcode as direct index into the table.  This will
give constant time lookup performance as the number of supported
opcodes increases.  Make the tables const as they are only ever read.
For uasm-mips.c sort the table alphabetically, and remove duplicate
entries, uasm-micromips.c was already sorted and duplicate free.
There is a small savings in object size as struct insn loses a field:

$ size arch/mips/mm/uasm-mips.o arch/mips/mm/uasm-mips.o.save
   text	   data	    bss	    dec	    hex	filename
  10040	      0	      0	  10040	   2738	arch/mips/mm/uasm-mips.o
   9240	   1120	      0	  10360	   2878	arch/mips/mm/uasm-mips.o.save

Signed-off-by: David Daney <david.daney@cavium.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Matt Redfearn <matt.redfearn@imgtec.com>
Cc: netdev@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/16365/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

1 files changed, 92 insertions, 96 deletions

diff --git a/arch/mips/mm/uasm-micromips.c b/arch/mips/mm/uasm-micromips.c
index 277cf52..c28ff53 100644
--- a/arch/mips/mm/uasm-micromips.c
+++ b/arch/mips/mm/uasm-micromips.c
@@ -40,93 +40,92 @@
 
 #include "uasm.c"
 
-static struct insn insn_table_MM[] = {
-	{ insn_addu, M(mm_pool32a_op, 0, 0, 0, 0, mm_addu32_op), RT | RS | RD },
-	{ insn_addiu, M(mm_addiu32_op, 0, 0, 0, 0, 0), RT | RS | SIMM },
-	{ insn_and, M(mm_pool32a_op, 0, 0, 0, 0, mm_and_op), RT | RS | RD },
-	{ insn_andi, M(mm_andi32_op, 0, 0, 0, 0, 0), RT | RS | UIMM },
-	{ insn_beq, M(mm_beq32_op, 0, 0, 0, 0, 0), RS | RT | BIMM },
-	{ insn_beql, 0, 0 },
-	{ insn_bgez, M(mm_pool32i_op, mm_bgez_op, 0, 0, 0, 0), RS | BIMM },
-	{ insn_bgezl, 0, 0 },
-	{ insn_bltz, M(mm_pool32i_op, mm_bltz_op, 0, 0, 0, 0), RS | BIMM },
-	{ insn_bltzl, 0, 0 },
-	{ insn_bne, M(mm_bne32_op, 0, 0, 0, 0, 0), RT | RS | BIMM },
-	{ insn_cache, M(mm_pool32b_op, 0, 0, mm_cache_func, 0, 0), RT | RS | SIMM },
-	{ insn_cfc1, M(mm_pool32f_op, 0, 0, 0, mm_cfc1_op, mm_32f_73_op), RT | RS },
-	{ insn_cfcmsa, M(mm_pool32s_op, 0, msa_cfc_op, 0, 0, mm_32s_elm_op), RD | RE },
-	{ insn_ctc1, M(mm_pool32f_op, 0, 0, 0, mm_ctc1_op, mm_32f_73_op), RT | RS },
-	{ insn_ctcmsa, M(mm_pool32s_op, 0, msa_ctc_op, 0, 0, mm_32s_elm_op), RD | RE },
-	{ insn_daddu, 0, 0 },
-	{ insn_daddiu, 0, 0 },
-	{ insn_di, M(mm_pool32a_op, 0, 0, 0, mm_di_op, mm_pool32axf_op), RS },
-	{ insn_divu, M(mm_pool32a_op, 0, 0, 0, mm_divu_op, mm_pool32axf_op), RT | RS },
-	{ insn_dmfc0, 0, 0 },
-	{ insn_dmtc0, 0, 0 },
-	{ insn_dsll, 0, 0 },
-	{ insn_dsll32, 0, 0 },
-	{ insn_dsra, 0, 0 },
-	{ insn_dsrl, 0, 0 },
-	{ insn_dsrl32, 0, 0 },
-	{ insn_drotr, 0, 0 },
-	{ insn_drotr32, 0, 0 },
-	{ insn_dsubu, 0, 0 },
-	{ insn_eret, M(mm_pool32a_op, 0, 0, 0, mm_eret_op, mm_pool32axf_op), 0 },
-	{ insn_ins, M(mm_pool32a_op, 0, 0, 0, 0, mm_ins_op), RT | RS | RD | RE },
-	{ insn_ext, M(mm_pool32a_op, 0, 0, 0, 0, mm_ext_op), RT | RS | RD | RE },
-	{ insn_j, M(mm_j32_op, 0, 0, 0, 0, 0), JIMM },
-	{ insn_jal, M(mm_jal32_op, 0, 0, 0, 0, 0), JIMM },
-	{ insn_jalr, M(mm_pool32a_op, 0, 0, 0, mm_jalr_op, mm_pool32axf_op), RT | RS },
-	{ insn_jr, M(mm_pool32a_op, 0, 0, 0, mm_jalr_op, mm_pool32axf_op), RS },
-	{ insn_lb, M(mm_lb32_op, 0, 0, 0, 0, 0), RT | RS | SIMM },
-	{ insn_ld, 0, 0 },
-	{ insn_lh, M(mm_lh32_op, 0, 0, 0, 0, 0), RS | RS | SIMM },
-	{ insn_ll, M(mm_pool32c_op, 0, 0, (mm_ll_func << 1), 0, 0), RS | RT | SIMM },
-	{ insn_lld, 0, 0 },
-	{ insn_lui, M(mm_pool32i_op, mm_lui_op, 0, 0, 0, 0), RS | SIMM },
-	{ insn_lw, M(mm_lw32_op, 0, 0, 0, 0, 0), RT | RS | SIMM },
-	{ insn_mfc0, M(mm_pool32a_op, 0, 0, 0, mm_mfc0_op, mm_pool32axf_op), RT | RS | RD },
-	{ insn_mfhi, M(mm_pool32a_op, 0, 0, 0, mm_mfhi32_op, mm_pool32axf_op), RS },
-	{ insn_mflo, M(mm_pool32a_op, 0, 0, 0, mm_mflo32_op, mm_pool32axf_op), RS },
-	{ insn_mtc0, M(mm_pool32a_op, 0, 0, 0, mm_mtc0_op, mm_pool32axf_op), RT | RS | RD },
-	{ insn_mthi, M(mm_pool32a_op, 0, 0, 0, mm_mthi32_op, mm_pool32axf_op), RS },
-	{ insn_mtlo, M(mm_pool32a_op, 0, 0, 0, mm_mtlo32_op, mm_pool32axf_op), RS },
-	{ insn_mul, M(mm_pool32a_op, 0, 0, 0, 0, mm_mul_op), RT | RS | RD },
-	{ insn_or, M(mm_pool32a_op, 0, 0, 0, 0, mm_or32_op), RT | RS | RD },
-	{ insn_ori, M(mm_ori32_op, 0, 0, 0, 0, 0), RT | RS | UIMM },
-	{ insn_pref, M(mm_pool32c_op, 0, 0, (mm_pref_func << 1), 0, 0), RT | RS | SIMM },
-	{ insn_rfe, 0, 0 },
-	{ insn_sc, M(mm_pool32c_op, 0, 0, (mm_sc_func << 1), 0, 0), RT | RS | SIMM },
-	{ insn_scd, 0, 0 },
-	{ insn_sd, 0, 0 },
-	{ insn_sll, M(mm_pool32a_op, 0, 0, 0, 0, mm_sll32_op), RT | RS | RD },
-	{ insn_sllv, M(mm_pool32a_op, 0, 0, 0, 0, mm_sllv32_op), RT | RS | RD },
-	{ insn_slt, M(mm_pool32a_op, 0, 0, 0, 0, mm_slt_op), RT | RS | RD },
-	{ insn_sltiu, M(mm_sltiu32_op, 0, 0, 0, 0, 0), RT | RS | SIMM },
-	{ insn_sltu, M(mm_pool32a_op, 0, 0, 0, 0, mm_sltu_op), RT | RS | RD },
-	{ insn_sra, M(mm_pool32a_op, 0, 0, 0, 0, mm_sra_op), RT | RS | RD },
-	{ insn_srl, M(mm_pool32a_op, 0, 0, 0, 0, mm_srl32_op), RT | RS | RD },
-	{ insn_srlv, M(mm_pool32a_op, 0, 0, 0, 0, mm_srlv32_op), RT | RS | RD },
-	{ insn_rotr, M(mm_pool32a_op, 0, 0, 0, 0, mm_rotr_op), RT | RS | RD },
-	{ insn_subu, M(mm_pool32a_op, 0, 0, 0, 0, mm_subu32_op), RT | RS | RD },
-	{ insn_sw, M(mm_sw32_op, 0, 0, 0, 0, 0), RT | RS | SIMM },
-	{ insn_sync, M(mm_pool32a_op, 0, 0, 0, mm_sync_op, mm_pool32axf_op), RS },
-	{ insn_tlbp, M(mm_pool32a_op, 0, 0, 0, mm_tlbp_op, mm_pool32axf_op), 0 },
-	{ insn_tlbr, M(mm_pool32a_op, 0, 0, 0, mm_tlbr_op, mm_pool32axf_op), 0 },
-	{ insn_tlbwi, M(mm_pool32a_op, 0, 0, 0, mm_tlbwi_op, mm_pool32axf_op), 0 },
-	{ insn_tlbwr, M(mm_pool32a_op, 0, 0, 0, mm_tlbwr_op, mm_pool32axf_op), 0 },
-	{ insn_wait, M(mm_pool32a_op, 0, 0, 0, mm_wait_op, mm_pool32axf_op), SCIMM },
-	{ insn_wsbh, M(mm_pool32a_op, 0, 0, 0, mm_wsbh_op, mm_pool32axf_op), RT | RS },
-	{ insn_xor, M(mm_pool32a_op, 0, 0, 0, 0, mm_xor32_op), RT | RS | RD },
-	{ insn_xori, M(mm_xori32_op, 0, 0, 0, 0, 0), RT | RS | UIMM },
-	{ insn_dins, 0, 0 },
-	{ insn_dinsm, 0, 0 },
-	{ insn_syscall, M(mm_pool32a_op, 0, 0, 0, mm_syscall_op, mm_pool32axf_op), SCIMM},
-	{ insn_bbit0, 0, 0 },
-	{ insn_bbit1, 0, 0 },
-	{ insn_lwx, 0, 0 },
-	{ insn_ldx, 0, 0 },
-	{ insn_invalid, 0, 0 }
+static const struct insn const insn_table_MM[insn_invalid] = {
+	[insn_addu]	= {M(mm_pool32a_op, 0, 0, 0, 0, mm_addu32_op), RT | RS | RD},
+	[insn_addiu]	= {M(mm_addiu32_op, 0, 0, 0, 0, 0), RT | RS | SIMM},
+	[insn_and]	= {M(mm_pool32a_op, 0, 0, 0, 0, mm_and_op), RT | RS | RD},
+	[insn_andi]	= {M(mm_andi32_op, 0, 0, 0, 0, 0), RT | RS | UIMM},
+	[insn_beq]	= {M(mm_beq32_op, 0, 0, 0, 0, 0), RS | RT | BIMM},
+	[insn_beql]	= {0, 0},
+	[insn_bgez]	= {M(mm_pool32i_op, mm_bgez_op, 0, 0, 0, 0), RS | BIMM},
+	[insn_bgezl]	= {0, 0},
+	[insn_bltz]	= {M(mm_pool32i_op, mm_bltz_op, 0, 0, 0, 0), RS | BIMM},
+	[insn_bltzl]	= {0, 0},
+	[insn_bne]	= {M(mm_bne32_op, 0, 0, 0, 0, 0), RT | RS | BIMM},
+	[insn_cache]	= {M(mm_pool32b_op, 0, 0, mm_cache_func, 0, 0), RT | RS | SIMM},
+	[insn_cfc1]	= {M(mm_pool32f_op, 0, 0, 0, mm_cfc1_op, mm_32f_73_op), RT | RS},
+	[insn_cfcmsa]	= {M(mm_pool32s_op, 0, msa_cfc_op, 0, 0, mm_32s_elm_op), RD | RE},
+	[insn_ctc1]	= {M(mm_pool32f_op, 0, 0, 0, mm_ctc1_op, mm_32f_73_op), RT | RS},
+	[insn_ctcmsa]	= {M(mm_pool32s_op, 0, msa_ctc_op, 0, 0, mm_32s_elm_op), RD | RE},
+	[insn_daddu]	= {0, 0},
+	[insn_daddiu]	= {0, 0},
+	[insn_di]	= {M(mm_pool32a_op, 0, 0, 0, mm_di_op, mm_pool32axf_op), RS},
+	[insn_divu]	= {M(mm_pool32a_op, 0, 0, 0, mm_divu_op, mm_pool32axf_op), RT | RS},
+	[insn_dmfc0]	= {0, 0},
+	[insn_dmtc0]	= {0, 0},
+	[insn_dsll]	= {0, 0},
+	[insn_dsll32]	= {0, 0},
+	[insn_dsra]	= {0, 0},
+	[insn_dsrl]	= {0, 0},
+	[insn_dsrl32]	= {0, 0},
+	[insn_drotr]	= {0, 0},
+	[insn_drotr32]	= {0, 0},
+	[insn_dsubu]	= {0, 0},
+	[insn_eret]	= {M(mm_pool32a_op, 0, 0, 0, mm_eret_op, mm_pool32axf_op), 0},
+	[insn_ins]	= {M(mm_pool32a_op, 0, 0, 0, 0, mm_ins_op), RT | RS | RD | RE},
+	[insn_ext]	= {M(mm_pool32a_op, 0, 0, 0, 0, mm_ext_op), RT | RS | RD | RE},
+	[insn_j]	= {M(mm_j32_op, 0, 0, 0, 0, 0), JIMM},
+	[insn_jal]	= {M(mm_jal32_op, 0, 0, 0, 0, 0), JIMM},
+	[insn_jalr]	= {M(mm_pool32a_op, 0, 0, 0, mm_jalr_op, mm_pool32axf_op), RT | RS},
+	[insn_jr]	= {M(mm_pool32a_op, 0, 0, 0, mm_jalr_op, mm_pool32axf_op), RS},
+	[insn_lb]	= {M(mm_lb32_op, 0, 0, 0, 0, 0), RT | RS | SIMM},
+	[insn_ld]	= {0, 0},
+	[insn_lh]	= {M(mm_lh32_op, 0, 0, 0, 0, 0), RS | RS | SIMM},
+	[insn_ll]	= {M(mm_pool32c_op, 0, 0, (mm_ll_func << 1), 0, 0), RS | RT | SIMM},
+	[insn_lld]	= {0, 0},
+	[insn_lui]	= {M(mm_pool32i_op, mm_lui_op, 0, 0, 0, 0), RS | SIMM},
+	[insn_lw]	= {M(mm_lw32_op, 0, 0, 0, 0, 0), RT | RS | SIMM},
+	[insn_mfc0]	= {M(mm_pool32a_op, 0, 0, 0, mm_mfc0_op, mm_pool32axf_op), RT | RS | RD},
+	[insn_mfhi]	= {M(mm_pool32a_op, 0, 0, 0, mm_mfhi32_op, mm_pool32axf_op), RS},
+	[insn_mflo]	= {M(mm_pool32a_op, 0, 0, 0, mm_mflo32_op, mm_pool32axf_op), RS},
+	[insn_mtc0]	= {M(mm_pool32a_op, 0, 0, 0, mm_mtc0_op, mm_pool32axf_op), RT | RS | RD},
+	[insn_mthi]	= {M(mm_pool32a_op, 0, 0, 0, mm_mthi32_op, mm_pool32axf_op), RS},
+	[insn_mtlo]	= {M(mm_pool32a_op, 0, 0, 0, mm_mtlo32_op, mm_pool32axf_op), RS},
+	[insn_mul]	= {M(mm_pool32a_op, 0, 0, 0, 0, mm_mul_op), RT | RS | RD},
+	[insn_or]	= {M(mm_pool32a_op, 0, 0, 0, 0, mm_or32_op), RT | RS | RD},
+	[insn_ori]	= {M(mm_ori32_op, 0, 0, 0, 0, 0), RT | RS | UIMM},
+	[insn_pref]	= {M(mm_pool32c_op, 0, 0, (mm_pref_func << 1), 0, 0), RT | RS | SIMM},
+	[insn_rfe]	= {0, 0},
+	[insn_sc]	= {M(mm_pool32c_op, 0, 0, (mm_sc_func << 1), 0, 0), RT | RS | SIMM},
+	[insn_scd]	= {0, 0},
+	[insn_sd]	= {0, 0},
+	[insn_sll]	= {M(mm_pool32a_op, 0, 0, 0, 0, mm_sll32_op), RT | RS | RD},
+	[insn_sllv]	= {M(mm_pool32a_op, 0, 0, 0, 0, mm_sllv32_op), RT | RS | RD},
+	[insn_slt]	= {M(mm_pool32a_op, 0, 0, 0, 0, mm_slt_op), RT | RS | RD},
+	[insn_sltiu]	= {M(mm_sltiu32_op, 0, 0, 0, 0, 0), RT | RS | SIMM},
+	[insn_sltu]	= {M(mm_pool32a_op, 0, 0, 0, 0, mm_sltu_op), RT | RS | RD},
+	[insn_sra]	= {M(mm_pool32a_op, 0, 0, 0, 0, mm_sra_op), RT | RS | RD},
+	[insn_srl]	= {M(mm_pool32a_op, 0, 0, 0, 0, mm_srl32_op), RT | RS | RD},
+	[insn_srlv]	= {M(mm_pool32a_op, 0, 0, 0, 0, mm_srlv32_op), RT | RS | RD},
+	[insn_rotr]	= {M(mm_pool32a_op, 0, 0, 0, 0, mm_rotr_op), RT | RS | RD},
+	[insn_subu]	= {M(mm_pool32a_op, 0, 0, 0, 0, mm_subu32_op), RT | RS | RD},
+	[insn_sw]	= {M(mm_sw32_op, 0, 0, 0, 0, 0), RT | RS | SIMM},
+	[insn_sync]	= {M(mm_pool32a_op, 0, 0, 0, mm_sync_op, mm_pool32axf_op), RS},
+	[insn_tlbp]	= {M(mm_pool32a_op, 0, 0, 0, mm_tlbp_op, mm_pool32axf_op), 0},
+	[insn_tlbr]	= {M(mm_pool32a_op, 0, 0, 0, mm_tlbr_op, mm_pool32axf_op), 0},
+	[insn_tlbwi]	= {M(mm_pool32a_op, 0, 0, 0, mm_tlbwi_op, mm_pool32axf_op), 0},
+	[insn_tlbwr]	= {M(mm_pool32a_op, 0, 0, 0, mm_tlbwr_op, mm_pool32axf_op), 0},
+	[insn_wait]	= {M(mm_pool32a_op, 0, 0, 0, mm_wait_op, mm_pool32axf_op), SCIMM},
+	[insn_wsbh]	= {M(mm_pool32a_op, 0, 0, 0, mm_wsbh_op, mm_pool32axf_op), RT | RS},
+	[insn_xor]	= {M(mm_pool32a_op, 0, 0, 0, 0, mm_xor32_op), RT | RS | RD},
+	[insn_xori]	= {M(mm_xori32_op, 0, 0, 0, 0, 0), RT | RS | UIMM},
+	[insn_dins]	= {0, 0},
+	[insn_dinsm]	= {0, 0},
+	[insn_syscall]	= {M(mm_pool32a_op, 0, 0, 0, mm_syscall_op, mm_pool32axf_op), SCIMM},
+	[insn_bbit0]	= {0, 0},
+	[insn_bbit1]	= {0, 0},
+	[insn_lwx]	= {0, 0},
+	[insn_ldx]	= {0, 0},
 };
 
 #undef M
@@ -156,20 +155,17 @@ static inline u32 build_jimm(u32 arg)
  */
 static void build_insn(u32 **buf, enum opcode opc, ...)
 {
-	struct insn *ip = NULL;
-	unsigned int i;
+	const struct insn *ip;
 	va_list ap;
 	u32 op;
 
-	for (i = 0; insn_table_MM[i].opcode != insn_invalid; i++)
-		if (insn_table_MM[i].opcode == opc) {
-			ip = &insn_table_MM[i];
-			break;
-		}
-
-	if (!ip || (opc == insn_daddiu && r4k_daddiu_bug()))
+	if (opc < 0 || opc >= insn_invalid ||
+	    (opc == insn_daddiu && r4k_daddiu_bug()) ||
+	    (insn_table_MM[opc].match == 0 && insn_table_MM[opc].fields == 0))
 		panic("Unsupported Micro-assembler instruction %d", opc);
 
+	ip = &insn_table_MM[opc];
+
 	op = ip->match;
 	va_start(ap, opc);
 	if (ip->fields & RS) {