There is a discrepancy in binutils between the assembler and disassembler regarding the memory size used for the 'cvttps2pi' instruction in x86-32 Intel syntax. The assembler accepts "XMMWORD PTR" but not "QWORD PTR": $ cat cvttps2pi.S .intel_syntax noprefix cvttps2pi mm0, XMMWORD PTR [eax] cvttps2pi mm0, QWORD PTR [eax] $ as --32 cvttps2pi.S -o cvttps2pi.o cvttps2pi.S: Assembler messages: cvttps2pi.S:3: Error: ambiguous operand size or operands invalid for `cvttps2pi' Whereas the disassembler produces "QWORD PTR": $ cat cvttps2pi.S .intel_syntax noprefix cvttps2pi mm0, XMMWORD PTR [eax] $ as --32 cvttps2pi.S -o cvttps2pi.o $ objdump -M intel -d cvttps2pi.o ... 0: 0f 2c 00 cvttps2pi mm0,QWORD PTR [eax] This happens with binutils 2.20.1 and with HEAD (as of today). The correct size seems to be "QWORD PTR", based on the AMD manual, which specifies the instruction's memory size as "mem64": CVTTPS2PI mmx, xmm/mem64 0F 2C /r
I have hit this problem with --cut here-- .intel_syntax noprefix cvtps2pi %mm0, QWORD PTR [rbp-16] cvttps2pi %mm0, QWORD PTR [rbp-16] --cut here-- $ as adds.s adds.s: Assembler messages: adds.s:3: Error: operand size mismatch for `cvttps2pi' $ as --version GNU assembler version 2.23.52.0.1-9.fc19 20130226
CVSROOT: /cvs/src Module name: src Changes by: hjl@sourceware.org 2013-07-08 16:24:21 Modified files: gas/testsuite : ChangeLog gas/testsuite/gas/i386: simd-intel.d simd.d simd.s opcodes : ChangeLog i386-opc.tbl i386-tbl.h Log message: Replace Xmmword with Qword on cvttps2pi gas/testsuite/ PR gas/13572 * gas/i386/simd.s: Add a test for cvttps2pi. * gas/i386/simd-intel.d: Updated. * gas/i386/simd.d: Likewise. opcodes/ PR gas/13572 * i386-opc.tbl: Replace Xmmword with Qword on cvttps2pi. * i386-tbl.h: Regenerated. Patches: http://sourceware.org/cgi-bin/cvsweb.cgi/src/gas/testsuite/ChangeLog.diff?cvsroot=src&r1=1.2269&r2=1.2270 http://sourceware.org/cgi-bin/cvsweb.cgi/src/gas/testsuite/gas/i386/simd-intel.d.diff?cvsroot=src&r1=1.11&r2=1.12 http://sourceware.org/cgi-bin/cvsweb.cgi/src/gas/testsuite/gas/i386/simd.d.diff?cvsroot=src&r1=1.11&r2=1.12 http://sourceware.org/cgi-bin/cvsweb.cgi/src/gas/testsuite/gas/i386/simd.s.diff?cvsroot=src&r1=1.11&r2=1.12 http://sourceware.org/cgi-bin/cvsweb.cgi/src/opcodes/ChangeLog.diff?cvsroot=src&r1=1.1988&r2=1.1989 http://sourceware.org/cgi-bin/cvsweb.cgi/src/opcodes/i386-opc.tbl.diff?cvsroot=src&r1=1.111&r2=1.112 http://sourceware.org/cgi-bin/cvsweb.cgi/src/opcodes/i386-tbl.h.diff?cvsroot=src&r1=1.117&r2=1.118
Fixed in 2.24.