From af8fcdb3d748b130919e60c1d3a6172d27e487cd Mon Sep 17 00:00:00 2001 From: jam1garner Date: Tue, 31 Jan 2023 00:53:05 -0500 Subject: fix 24-bit branch immediate decoding --- src/armv7.rs | 14 ++++++++++---- 1 file changed, 10 insertions(+), 4 deletions(-) (limited to 'src/armv7.rs') diff --git a/src/armv7.rs b/src/armv7.rs index c2254a5..276b807 100644 --- a/src/armv7.rs +++ b/src/armv7.rs @@ -3815,20 +3815,26 @@ impl Decoder for InstDecoder { ]; } else if op < 0b110000 { // 10xxxx - // the + 1 is to compensate for an architecturally-defined initial offset inst.opcode = Opcode::B; + + // the + 2 is to compensate for an architecturally-defined initial offset + let imm24 = ((((word & 0x00ff_ffff) + 2) << 8) as i32) >> 8; + inst.operands = [ - Operand::BranchOffset(((word & 0x00ffff) + 1) as i16 as i32), + Operand::BranchOffset(imm24), Operand::Nothing, Operand::Nothing, Operand::Nothing, ]; } else { // 11xxxx - // the + 1 is to compensate for an architecturally-defined initial offset + + // the + 2 is to compensate for an architecturally-defined initial offset + let imm24 = ((((word & 0x00ff_ffff) + 2) << 8) as i32) >> 8; + inst.opcode = Opcode::BL; inst.operands = [ - Operand::BranchOffset(((word & 0x00ffff) + 1) as i16 as i32), + Operand::BranchOffset(imm24), Operand::Nothing, Operand::Nothing, Operand::Nothing, -- cgit v1.1