tcg: Tidy generated code for tcg_outN

Aliasing was forcing s->code_ptr to be re-read after the store.
Keep the pointer in a local variable to help the compiler.

Signed-off-by: Richard Henderson <rth@twiddle.net>
tcg-i386: Add and use tcg_out64

No point in splitting the write into 32-bit pieces.

Reviewed-by: Aurelien Jarno <aurelien@aurel32.net>
Signed-off-by: Richard Henderson <rth@twiddle.net>
tcg-i386: Try pc-relative lea for constant formation

Use a 7 byte lea before the ultimate 10 byte movq.

Signed-off-by: Richard Henderson <rth@twiddle.net>
tcg-i386: Tidy qemu_ld/st slow path

Use existing stack space for arguments; don't push/pop.
Use less ifdefs and more C ifs.

Signed-off-by: Richard Henderson <rth@twiddle.net>
tcg: Add mmu helpers that take a return address argument

Allow the code that tcg generates to be less obtuse, passing in
the return address directly instead of computing it in the helper.

Maintain the old entrance point unchanged as an alternate entry point.

Delete the helper_st*_cmmu prototypes; the implementations did not exist.

Signed-off-by: Richard Henderson <rth@twiddle.net>
tcg: Tidy softmmu_template.h

Avoid a loop in the tlb_fill path; the fill will either succeed or
generate an exception.

Inline the slow_ld/st function; it was a complete copy of the main
helper except for the actual cross-page unaligned code, and the
compiler was inlining it anyway.

Add unlikely markers optimizing for the most common case of simple
tlb miss.

Make sure the compiler can optimize away the unaligned paths for a
1 byte access.

Reviewed-by: Aurelien Jarno <aurelien@aurel32.net>
Signed-off-by: Richard Henderson <rth@twiddle.net>
tcg-i386: Use new return-argument ld/st helpers

Discontinue the jump-around-jump-to-jump scheme, trading it for a single
immediate move instruction.  The two extra jumps always consume 7 bytes,
whereas the immediate move is either 5 or 7 bytes depending on where the
code_gen_buffer gets located.

Signed-off-by: Richard Henderson <rth@twiddle.net>
tcg-arm: Use ldrd/strd for appropriate qemu_ld/st64

Signed-off-by: Richard Henderson <rth@twiddle.net>
tcg-arm: Rearrange slow-path qemu_ld/st

Instead of using a branch-call-branch sequence, arrange for a
call-branch sequence, using the ARM's conditional call insn.
This reduces the size of the slow-path within the TB, and makes
the GETPC_EXT implementation identical for TCG and not-TCG.

Signed-off-by: Richard Henderson <rth@twiddle.net>