// Test of BL and BR instructions.
// Requires:
// BL, BR, ADDI & B instructions
// Expected results:
// X0  = 1
// X1  = 0
// X2  = 0 (anything else indicates an error)
// X3  = 1 (signifies program end was reached)
// X4  = 52
// X5  = 64
// X29 = 20
// X30 = 68

//ADDI: I-type, Reg[Rd] = Reg[Rn] + {'0, Imm12}
//OP         Imm12        Rn    Rd
//3322222222 221111111111 00000 00000
//1098765432 109876543210 98765 43210
//1001000100 Unsigned     0..31 0..31

//B: B-type, PC = PC + SignExtend({Imm26, 2'b00})
//OP     Imm26
//332222 22222211111111110000000000
//109876 54321098765432109876543210
//000101 2's Comp Imm26

//BL: B-type, PC = PC + SignExtend({Imm26, 2'b00}), X30 = PC + 4  (load into pc - 4 for pipline?)
//OP     Imm26
//332222 22222211111111110000000000
//109876 54321098765432109876543210
//100101 2's Comp Imm26

//BR: R-type, PC = Reg[Rd]
//OP          Rm    Shamt  Rn    Rd
//33222222222 21111 111111 00000 00000
//10987654321 09876 543210 98765 43210
//11010110000 0..31 000000 0..31 0..31

            // MAIN:
1001000100_000000000001_11111_00000    //  0: ADDI X0, X31, #1        // X0 = 1
1001000100_000000000000_11111_00001    //  4: ADDI X1, X31, #0        // X1 = 0
1001000100_000000000000_11111_00010    //  8: ADDI X2, X31, #0        // X2 = 0
1001000100_000000000000_11111_00011    // 12: ADDI X3, X31, #0        // X3 = 0
100101_00000000000000000000000101      // 16: BL BL_FORWARDS (+5)     // X30 = 20
            // BL_BACKWARDS:
1001000100_000000110100_11111_00100    // 20: ADDI X4, X31, #52       // X4 = 52
11010110000_00000_000000_00000_00100   // 24: BR X4 (ALMOST_THERE)
1001000100_000000000000_11111_11111    // 28: ADDI X31, X31, #0       // Noop
            // BR_ERROR (SHOULD NOT EVER EXECUTE):
1001000100_000000000001_11111_00010    // 32: ADDI X2, X31, #1        // X2 = 1 (Error flag)
            // BL_FORWARDS:
1001000100_000000000000_11110_11101    // 36: ADDI X29, X30, #0       // X29 = 20
1001000100_000001000000_11111_00101    // 40: ADDI X5, X31, #64       // X5 = 64
100101_11111111111111111111111010      // 44: BL BL_BACKWARDS (-6)    // X30 = 48
1001000100_000000000000_11111_11111    // 48: ADDI X31, X31, #0       // Noop
            // ALMOST_THERE:
11010110000_00000_000000_00000_00101   // 52: BR X5 (END)
1001000100_000000000000_11111_11111    // 56: ADDI X31, X31, #0       // Noop
            // BR_ERROR (SHOULD NOT EVER EXECUTE):
1001000100_000000000001_11111_00010    // 60: ADDI X2, X31, #1        // X2 = 1 (Error flag)
            // END:
100101_00000000000000000000000010      // 64: BL FINAL (+2)           // X30 = 68
1001000100_000000000000_11111_11111    // 68: ADDI X31, X31, #0       // Noop
	    // FINAL:
1001000100_000000000001_11111_00011    // 72: ADDI X3, X31, #1        // X3 = 1
000101_00000000000000000000000000      // 76: B HALT (0)
1001000100_000000000000_11111_11111    // 80: ADDI X31, X31, #0       // Noop
            // BL/BR_ERROR (SHOULD NOT EVER EXECUTE):
1001000100_000000000001_11111_00010    // 84: ADDI X2, X31, #1        // X2 = 1 (Error flag)