10 Commits

Author SHA1 Message Date
Andrew Kelley
91c4e28c51 Liveness: fix br instruction not tracking its operand 2021-07-20 16:04:46 -07:00
Andrew Kelley
a97e5e119a stage2: switch: fix Sema bugs and implement AIR printing 2021-07-20 12:19:17 -07:00
Andrew Kelley
d17f492017 stage2: miscellaneous fixes for the branch
* Breaking language change: inline assembly must use string literal
   syntax. This is in preparation for inline assembly improvements that
   involve more integration with the Zig language. This means we cannot
   rely on text substitution.
 * Liveness: properly handle inline assembly and function calls with
   more than 3 operands.
   - More than 35 operands is not yet supported. This is a low priority
     to implement.
   - This required implementation in codegen.zig as well.
 * Liveness: fix bug causing incorrect tomb bits.
 * Sema: enable switch expressions that are evaluated at compile-time.
   - Runtime switch instructions still need to be reworked in this
     branch. There was a TODO left here (by me) with a suggestion to do
     some bigger changes as part of the AIR memory reworking. Now that
     time has come and I plan to honor the suggestion in a future commit
     before merging this branch.
 * AIR printing: fix missing ')' on alive instructions.

We're back to "hello world" working for the x86_64 backend.
2021-07-20 12:19:16 -07:00
Andrew Kelley
8082660118 stage2: codegen.zig updated to new AIR memory layout 2021-07-20 12:19:16 -07:00
Andrew Kelley
c020a30296 Sema: remove br_block_flat AIR instruction
Thanks to the new AIR memory layout, we can do this by turning a br
operand into a block, rather than having this special purpose
instruction.
2021-07-20 12:19:16 -07:00
Andrew Kelley
c09b973ec2 stage2: compile error fixes for AIR memory layout branch
Now the branch is compiling again, provided that one uses
`-Dskip-non-native`, but many code paths are disabled. The code paths
can now be re-enabled one at a time and updated to conform to the new
AIR memory layout.
2021-07-20 12:19:16 -07:00
Andrew Kelley
0f38f68696 stage2: Air and Liveness are passed ephemerally
to the link infrastructure, instead of being stored with Module.Fn. This
moves towards a strategy to make more efficient use of memory by not
storing Air or Liveness data in the Fn struct, but computing it on
demand, immediately sending it to the backend, and then immediately
freeing it.

Backends which want to defer codegen until flush() such as SPIR-V
must move the Air/Liveness data upon `updateFunc` being called and keep
track of that data in the backend implementation itself.
2021-07-20 12:19:16 -07:00
Andrew Kelley
ee6432537e stage2: first pass over codegen.zig for AIR memory layout 2021-07-20 12:19:16 -07:00
Andrew Kelley
ef7080aed1 stage2: update Liveness, SPIR-V for new AIR memory layout
also do the inline assembly instruction
2021-07-20 12:19:16 -07:00
Andrew Kelley
3c3abaf390 stage2: update liveness analysis to new AIR memory layout
It's pretty compact, with each AIR instruction only taking up 4 bits,
plus a sparse table for special instructions such as conditional branch,
switch branch, and function calls with more than 2 arguments.
2021-07-20 12:18:14 -07:00