Make cmd/internal/obj/x86 support 32-bit mode and use
instead of cmd/internal/obj/i386. Delete cmd/internal/obj/i386.
Clean up encoding of PINSRQ, CMPSD to use explicit third arg
instead of jamming it into an unused slot of a different arg.
Also fix bug in old6a, which declared the wrong grammar.
The accepted (and encoded) arguments to CMPSD etc are mem,reg not reg,mem.
Code that did try to use mem,reg before would be rejected by liblink,
so only reg,reg ever worked, so existing code is not affected.
After this change, code can use mem,reg successfully.
The real bug here is that the encoding tables inverted the argument
order, making the comparisons all backward from what they say on the page.
It's too late to swap them, though: people have already written code that
expects the inverted comparisons (like in package math, and likely externally).
The best we can do is make the argument that should and can take a
memory operand accept it.
Bit-for-bit compatibility checked against tree without this CL.
Change-Id: Ife5685bc98c95001f64407f35066b34b4dae11c1
Reviewed-on: https://go-review.googlesource.com/6810
Reviewed-by: Rob Pike <r@golang.org>
This CL will break any uses of 'go tool 5a' etc.
That is intentional.
Code that invokes an assembler directly should be updated to use go tool asm.
We plan to keep the old5a around for bit-for-bit verification during
the release testing phase, but we plan to remove those tools for the
actual release. Renaming the directory now makes sure that lingering
references to 'go tool 5a' will be caught, changed to use asm, and
tested during the release evaluation.
Change-Id: I98748a7ddb34cc7f1b151c2ef421d3656821f5c2
Reviewed-on: https://go-review.googlesource.com/6366
Reviewed-by: Rob Pike <r@golang.org>
