http://llvm.org/bugs/show_bug.cgi?id=14056
Bug #: 14056
Summary: Incorrect assembly of MOV/MOVABS instructions with
64-bit displacements
Product: new-bugs
Version: trunk
Platform: Macintosh
OS/Version: MacOS X
Status: NEW
Severity: normal
Priority: P
Component: new bugs
AssignedTo: [email protected]
ReportedBy: [email protected]
CC: [email protected]
Classification: Unclassified
I'm not sure if this should be filed on this Bugzilla or not, but it seems to
be related to Clang's internal x86 assembler — at least I don't see Clang
calling out to any external assembler in the -v output.
.code64
movabsq 0x123456789abcdef, %rax
movq 0x123456789abcdef, %rax
GCC's assembler produces the expected output:
48 a1 ef cd ab 89 67 45 23 01 // movabsq 0x123456789abcdef, %rax
48 8b 04 25 ef cd ab 89 // movq 0x89abcdef, %rax
with a compile-time warning about the truncated displacement in "movq".
Clang rejects the movabsq instruction with an error...
test.s:4:10: error: invalid operand for instruction
movabsq 0x123456789abcdef, %rax
^
...and *silently* miscompiles the "movq".
48 8b 04 25 ef cd ab 89 // movq 0x89abcdef, %rax
I'd like to see both issues addressed, but particularly the lack of MOVABS,
because it's very inconvenient to have to resort to ".byte" directives in the
case of an instruction that's been around for ages.
--
Configure bugmail: http://llvm.org/bugs/userprefs.cgi?tab=email
------- You are receiving this mail because: -------
You are on the CC list for the bug.
_______________________________________________
LLVMbugs mailing list
[email protected]
http://lists.cs.uiuc.edu/mailman/listinfo/llvmbugs
