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authoriximeow <me@iximeow.net>2020-12-06 15:54:31 -0800
committeriximeow <me@iximeow.net>2020-12-06 15:54:31 -0800
commitc9f67f0f30cbd1459b80b2d8380fba3407e36bfa (patch)
tree454977f569696d4f913225cac8a54c4433c4bfb9 /src/armv7
parentfde906acd802e071c8a7f9435ea205692e4b26b4 (diff)
propagate up invalid thumb immediate expansion
Diffstat (limited to 'src/armv7')
-rw-r--r--src/armv7/thumb.rs20
1 files changed, 10 insertions, 10 deletions
diff --git a/src/armv7/thumb.rs b/src/armv7/thumb.rs
index d314d7e..0d2a36e 100644
--- a/src/armv7/thumb.rs
+++ b/src/armv7/thumb.rs
@@ -23,31 +23,31 @@ fn ROR_C(x: u32, shift: u16) -> (u32, bool) {
}
#[allow(non_snake_case)]
-fn ThumbExpandImm_C(imm: u16) -> u32 {
+fn ThumbExpandImm_C(imm: u16) -> Result<u32, DecodeError> {
if imm & 0b1100_0000_0000 == 0 {
let ty = (imm >> 8) & 0b11;
let imm_low = (imm & 0b11111111) as u32;
match ty {
0b00 => {
- imm_low
+ Ok(imm_low)
}
0b01 => {
if imm_low == 0 {
- panic!("unpredictable");
+ return Err(DecodeError::Unpredictable);
}
- (imm_low << 16) | imm_low
+ Ok((imm_low << 16) | imm_low)
}
0b10 => {
if imm_low == 0 {
- panic!("unpredictable");
+ return Err(DecodeError::Unpredictable);
}
- (imm_low << 24) | (imm_low << 8)
+ Ok((imm_low << 24) | (imm_low << 8))
}
0b11 => {
if imm_low == 0 {
- panic!("unpredictable");
+ return Err(DecodeError::Unpredictable);
}
- (imm_low << 24) | (imm_low << 16) | (imm_low << 8) | imm_low
+ Ok((imm_low << 24) | (imm_low << 16) | (imm_low << 8) | imm_low)
}
_ => {
unreachable!("impossible bit pattern");
@@ -58,7 +58,7 @@ fn ThumbExpandImm_C(imm: u16) -> u32 {
let rot = (imm >> 7) & 0b11111;
// TODO: figure out what to do with carry_out
let (imm32, _carry_out) = ROR_C(unrotated_value, rot);
- imm32
+ Ok(imm32)
}
}
@@ -1049,7 +1049,7 @@ pub fn decode_into<T: IntoIterator<Item=u8>>(decoder: &InstDecoder, inst: &mut I
inst.s = s;
- let imm = ThumbExpandImm_C(imm);
+ let imm = ThumbExpandImm_C(imm)?;
match op {
0b0000 => {