From 9d5f8ad8e637cd76ddae99115724b0e6a6aaa31f Mon Sep 17 00:00:00 2001 From: Clifford Wolf Date: Thu, 19 Nov 2015 04:02:00 +0100 Subject: [PATCH] Towards compressed ISA support --- firmware/irq.c | 3 ++- picorv32.v | 36 ++++++++++++++++++++++++++++++++++-- 2 files changed, 36 insertions(+), 3 deletions(-) diff --git a/firmware/irq.c b/firmware/irq.c index e67b16d..ec37614 100644 --- a/firmware/irq.c +++ b/firmware/irq.c @@ -31,7 +31,8 @@ uint32_t *irq(uint32_t *regs, uint32_t irqs) if ((irqs & 6) != 0) { uint32_t pc = regs[0] - 4; - uint32_t instr = *(uint32_t*)pc; + uint16_t *instr_hwords = (uint16_t*)pc; + uint32_t instr = instr_hwords[0] | (instr_hwords[1] << 16); print_str("\n"); print_str("------------------------------------------------------------\n"); diff --git a/picorv32.v b/picorv32.v index 3d60042..f3f5086 100644 --- a/picorv32.v +++ b/picorv32.v @@ -237,6 +237,10 @@ module picorv32 #( case (mem_rdata_latched[1:0]) 2'b00: begin // Quadrant 0 case (mem_rdata_latched[15:13]) + 3'b000: begin // C.ADDI4SPN + mem_rdata_q[14:12] <= 3'b000; + mem_rdata_q[31:20] <= {mem_rdata_latched[10:7], mem_rdata_latched[12:11], mem_rdata_latched[5], mem_rdata_latched[6]}; + end 3'b 110: begin // C.SW {mem_rdata_q[31:25], mem_rdata_q[11:7]} <= {mem_rdata_latched[5], mem_rdata_latched[12:10], mem_rdata_latched[6], 2'b00}; mem_rdata_q[14:12] <= 3'b 010; @@ -262,15 +266,21 @@ module picorv32 #( mem_rdata_q[31:12] <= $signed({mem_rdata_latched[12], mem_rdata_latched[6:2]}); end end + 3'b100: begin + if (mem_rdata_latched[11:10] == 2'b10) begin // C.ANDI + mem_rdata_q[14:12] <= 3'b111; + mem_rdata_q[31:20] <= $signed({mem_rdata_latched[12], mem_rdata_latched[6:2]}); + end + end 3'b 110: begin // C.BEQZ mem_rdata_q[14:12] <= 3'b000; - { mem_rdata_q[31], mem_rdata_q[7], mem_rdata_q[30:15], mem_rdata_q[11:8] } <= + { mem_rdata_q[31], mem_rdata_q[7], mem_rdata_q[30:25], mem_rdata_q[11:8] } <= $signed({mem_rdata_latched[12], mem_rdata_latched[6:5], mem_rdata_latched[2], mem_rdata_latched[11:10], mem_rdata_latched[4:3]}); end 3'b 111: begin // C.BNEZ mem_rdata_q[14:12] <= 3'b001; - { mem_rdata_q[31], mem_rdata_q[7], mem_rdata_q[30:15], mem_rdata_q[11:8] } <= + { mem_rdata_q[31], mem_rdata_q[7], mem_rdata_q[30:25], mem_rdata_q[11:8] } <= $signed({mem_rdata_latched[12], mem_rdata_latched[6:5], mem_rdata_latched[2], mem_rdata_latched[11:10], mem_rdata_latched[4:3]}); end @@ -295,6 +305,10 @@ module picorv32 #( mem_rdata_q[14:12] <= 3'b000; mem_rdata_q[31:20] <= 12'b0; end + if (mem_rdata_latched[12] != 0 && mem_rdata_latched[6:2] != 0) begin // C.ADD + mem_rdata_q[14:12] <= 3'b000; + mem_rdata_q[31:25] <= 7'b0000000; + end end 3'b110: begin // C.SWSP {mem_rdata_q[31:25], mem_rdata_q[11:7]} <= {mem_rdata_latched[8:7], mem_rdata_latched[12:9], 2'b00}; @@ -525,6 +539,11 @@ module picorv32 #( case (mem_rdata_latched[1:0]) 2'b00: begin // Quadrant 0 case (mem_rdata_latched[15:13]) + 3'b000: begin // C.ADDI4SPN + is_alu_reg_imm <= |mem_rdata_latched[12:5]; + decoded_rs1 <= 2; + decoded_rd <= 8 + mem_rdata_latched[9:7]; + end 3'b110: begin // C.SW is_sb_sh_sw <= 1; decoded_rs1 <= 8 + mem_rdata_latched[9:7]; @@ -559,6 +578,13 @@ module picorv32 #( decoded_rs1 <= 0; end end + 3'b100: begin + if (mem_rdata_latched[11:10] == 2'b10) begin // C.ANDI + is_alu_reg_imm <= 1; + decoded_rd <= 8 + mem_rdata_latched[9:7]; + decoded_rs1 <= 8 + mem_rdata_latched[9:7]; + end + end 3'b101: begin // C.J instr_jal <= 1; end @@ -598,6 +624,12 @@ module picorv32 #( decoded_rd <= 1; decoded_rs1 <= mem_rdata_latched[11:7]; end + if (mem_rdata_latched[12] != 0 && mem_rdata_latched[6:2] != 0) begin // C.ADD + is_alu_reg_reg <= 1; + decoded_rd <= mem_rdata_latched[11:7]; + decoded_rs1 <= mem_rdata_latched[11:7]; + decoded_rs2 <= mem_rdata_latched[6:2]; + end end 3'b110: begin // C.SWSP is_sb_sh_sw <= 1;