vhaudiquet
/
vriscv
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

Fix branch signextend + offset

Browse Source
master
vhaudiquet 1 year ago
parent 24ca9532d4
commit 57dfd9cb76
1 changed files with 8 additions and 9 deletions
Show all changes Ignore whitespace when comparing lines Ignore changes in amount of whitespace Ignore changes in whitespace at EOL
Show Stats Download Patch File Download Diff File
  1. 17
      src/cpu/rv32cpu.c

17
src/cpu/rv32cpu.c
Unescape View File

@ -150,7 +150,7 @@ static void cpu_execute(rv32_cpu_t* cpu, instruction_t* instruction)
{
// Branches ; to know which one, we must analyse func3
// Sign extend immediate from 13 bits to 32 bits
uint32_t immediate = (instruction->immediate & 0xFFF) | (instruction->immediate & 0x1000 ? 0xFFFFE000 : 0);
uint32_t immediate = (instruction->immediate & 0x1FFF) | (instruction->immediate & 0x1000 ? 0xFFFFE000 : 0);
immediate -= 4;
switch(instruction->func3)
@ -158,32 +158,32 @@ static void cpu_execute(rv32_cpu_t* cpu, instruction_t* instruction)
case FUNC3_BEQ:
// Branch EQual
if(cpu->regs.x[instruction->rs1] == cpu->regs.x[instruction->rs2])
cpu->pc = immediate;
cpu->pc += immediate;
break;
case FUNC3_BNE:
// Branch Not Equal
if(cpu->regs.x[instruction->rs1] != cpu->regs.x[instruction->rs2])
cpu->pc = immediate;
cpu->pc += immediate;
break;
case FUNC3_BLT:
// Branch Less Than
if(((int32_t) cpu->regs.x[instruction->rs1]) < ((int32_t) cpu->regs.x[instruction->rs2]))
cpu->pc = immediate;
cpu->pc += immediate;
break;
case FUNC3_BLTU:
// Branch Less Than Unsigned
if(cpu->regs.x[instruction->rs1] < cpu->regs.x[instruction->rs2])
cpu->pc = immediate;
cpu->pc += immediate;
break;
case FUNC3_BGE:
// Branch Greater Equal
if(((int32_t) cpu->regs.x[instruction->rs1]) >= ((int32_t) cpu->regs.x[instruction->rs2]))
cpu->pc = immediate;
cpu->pc += immediate;
break;
case FUNC3_BGEU:
// Branch Greater Equal Unsigned
if(cpu->regs.x[instruction->rs1] >= cpu->regs.x[instruction->rs2])
cpu->pc = immediate;
cpu->pc += immediate;
break;
default:
fprintf(stderr, "FATAL: Unknown func3 0x%x for branch instruction, could not execute\n", instruction->func3);
@ -621,8 +621,7 @@ static void cpu_print_instruction(instruction_t* instruction)
{
// Branches ; to know which one, we must analyse func3
// Sign extend immediate from 13 bits to 32 bits
uint32_t immediate = (instruction->immediate & 0xFFF) | (instruction->immediate & 0x1000 ? 0xFFFFE000 : 0);
immediate -= 4;
uint32_t immediate = (instruction->immediate & 0x1FFF) | (instruction->immediate & 0x1000 ? 0xFFFFE000 : 0);
switch(instruction->func3)
{

Write Preview
Loading…
Cancel
Save