Fix segfault due to b64 encoding (#919)

* Fix segfault due to b64 encoding Prior to this patch, bconst.b64 encoded its instruction with a 32-bit immediate that caused improper decoding of the MOV instruction; instead, use a REX prefix and rely on zero-extension of the immediate. Fixes #911.
2019-08-23 09:04:34 -07:00
parent 1eb6cd93b2
commit cc57e84cbd
3 changed files with 18 additions and 4 deletions
--- a/cranelift/codegen/meta/src/isa/x86/encodings.rs
+++ b/cranelift/codegen/meta/src/isa/x86/encodings.rs
@@ -683,10 +683,7 @@ pub fn define(
    for &ty in &[B1, B8, B16, B32] {
        e.enc_both(bconst.bind(ty), rec_pu_id_bool.opcodes(vec![0xb8]));
    }
-    e.enc64(
-        bconst.bind(B64),
-        rec_pu_id_bool.opcodes(vec![0xb8]).rex().w(),
-    );
+    e.enc64(bconst.bind(B64), rec_pu_id_bool.opcodes(vec![0xb8]).rex());

    // Shifts and rotates.
    // Note that the dynamic shift amount is only masked by 5 or 6 bits; the 8-bit