[libbluray-devel] [Git][videolan/libbluray][master] hdmv: fix INSN_BC instruction

[Petri Hintukainen (@hpi)]

Petri Hintukainen pushed to branch master at VideoLAN / libbluray


Commits:
ea3e318b by Hendrik Leppkes at 2026-08-21T17:08:57+00:00
hdmv: fix INSN_BC instruction

The condition was backwards, checking if any bits outside of the desired
are set, rather then the desired bits.

This still differs from the specification which just indicates a simple
AND check, however the spec does also not indicate if the result should
be checked to be non-zero, or matching the input.

This version is likely what was originally intended, however all discs
that were found to use the BC instruction only test a single bit, making
the difference between a full or partial match not testable.

- - - - -


1 changed file:

- src/libbluray/hdmv/hdmv_vm.c


Changes:

=====================================
src/libbluray/hdmv/hdmv_vm.c
=====================================
@@ -1134,7 +1134,7 @@ static int _hdmv_step(HDMV_VM *p)
                 BD_DEBUG(DBG_HDMV|DBG_CRIT, "missing operand in BRANCH/JUMP opcode 0x%08x\n", *(uint32_t*)insn);
             }
             switch (insn->cmp_opt) {
-                case INSN_BC: p->pc += !!(dst & ~src); break;
+                case INSN_BC: p->pc += !!(src & ~dst); break;
                 case INSN_EQ: p->pc += !(dst == src); break;
                 case INSN_NE: p->pc += !(dst != src); break;
                 case INSN_GE: p->pc += !(dst >= src); break;



View it on GitLab: https://code.videolan.org/videolan/libbluray/-/commit/ea3e318b89c42d2eff2ce0b9d78dc2371fbb6a67

-- 
View it on GitLab: https://code.videolan.org/videolan/libbluray/-/commit/ea3e318b89c42d2eff2ce0b9d78dc2371fbb6a67
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