.TH GASM-DIFF 1 "2026-09-19" "gasm" "User Commands"
.SH NAME
gasm-diff \- compare the machine code of two assembly files
.SH SYNOPSIS
.B gasm diff [\-GOARCH arch] [\-I dir] <file1.s> <file2.s>
.SH DESCRIPTION
Compare the machine code produced by assembling two files.  Shows which
functions differ and the byte-level differences.  Useful for verifying
that two implementations produce identical code, or for tracking
encoding changes between Go assembler versions.
.PP
Functions are paired by exact name unless
.B \-\-map
says otherwise, so
.B \-\-map wideCopyAVX2=wideCopyAVX512
pairs two variants regardless of suffix.
.SH OPTIONS
.TP
.B \-GOARCH \fIarch\fR
Target architecture for both files: amd64, arm64, riscv64 or loong64;
overrides the file-name suffixes.
.TP
.B \-I \fIdir\fR
Directory to search for #include files; may be repeated, searched in
order after the source directory.
.TP
.B \-\-map \fIspec\fR
Comma-separated old=new pairs to match functions with different names.
.SH EXIT STATUS
Exits 0 when every paired function is identical and 1 when anything
differs; a usage error exits 2.
.SH EXAMPLES
.nf
gasm diff hello_amd64.s hello_amd64.s
gasm diff \-\-map wideCopyAVX2=wideCopyAVX512 avx2_amd64.s avx512_amd64.s
.fi
.SH SEE ALSO
.BR gasm (1),
.BR gasm\-asm (1)