After much back and forth, I decided to deviate from ARM design and split LDR into 4 instructions (r + imm12, r + imm8, r + r << imm12, constantpool). The advantage of this is 1) it follows the latest ARM technical manual, and 2) makes it easier to reduce the width of the instruction later. The down side is this creates more inconsistency between the two sub-targets. We should split ARM LDR instruction in a similar fashion later. I've added a README entry for this.
llvm-svn: 74420
also some contribution from Jim Grosbach, Bob Wilson, and Evan Cheng.
I've done my best to consolidate the patches with those that were done by
Viktor Kutuzov and Anton Korzh from Access Softek, Inc. Let me know if missed
anything. I've completely reorganized the thumb2 td file, made more extensive
uses of multiclass, etc.
Test cases will be contributed later after I re-organize what's in svn first.
llvm-svn: 73965
- Change register allocation hint to a pair of unsigned integers. The hint type is zero (which means prefer the register specified as second part of the pair) or entirely target dependent.
- Allow targets to specify alternative register allocation orders based on allocation hint.
Part 2.
- Use the register allocation hint system to implement more aggressive load / store multiple formation.
- Aggressively form LDRD / STRD. These are formed *before* register allocation. It has to be done this way to shorten live interval of base and offset registers. e.g.
v1025 = LDR v1024, 0
v1026 = LDR v1024, 0
=>
v1025,v1026 = LDRD v1024, 0
If this transformation isn't done before allocation, v1024 will overlap v1025 which means it more difficult to allocate a register pair.
- Even with the register allocation hint, it may not be possible to get the desired allocation. In that case, the post-allocation load / store multiple pass must fix the ldrd / strd instructions. They can either become ldm / stm instructions or back to a pair of ldr / str instructions.
This is work in progress, not yet enabled.
llvm-svn: 73381
llvm.eh.sjlj.* for better clarity as to their purpose and scope. Add
a description of llvm.eh.sjlj.setjmp to ExceptionHandling.html.
(llvm.eh.sjlj.longjmp documentation coming when that implementation is
added).
llvm-svn: 71758
a supporting preliminary patch for GCC-compatible SjLJ exception handling. Note that these intrinsics are not designed to be invoked directly by the user, but
rather used by the front-end as target hooks for exception handling.
llvm-svn: 71610