Commit Graph

8 Commits

Author SHA1 Message Date
Guillaume Chatelet 48904e9452 [Alignment] Use llvm::Align in MachineFunction and TargetLowering - fixes mir parsing
Summary:
This catches malformed mir files which specify alignment as log2 instead of pow2.
See https://reviews.llvm.org/D65945 for reference,

This is patch is part of a series to introduce an Alignment type.
See this thread for context: http://lists.llvm.org/pipermail/llvm-dev/2019-July/133851.html
See this patch for the introduction of the type: https://reviews.llvm.org/D64790

Reviewers: courbet

Subscribers: MatzeB, qcolombet, dschuff, arsenm, sdardis, nemanjai, jvesely, nhaehnle, hiraditya, kbarton, asb, rbar, johnrusso, simoncook, apazos, sabuasal, niosHD, jrtc27, MaskRay, zzheng, edward-jones, atanasyan, rogfer01, MartinMosbeck, brucehoult, the_o, PkmX, jocewei, jsji, Petar.Avramovic, asbirlea, s.egerton, pzheng, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D67433

llvm-svn: 371608
2019-09-11 11:16:48 +00:00
Sander de Smalen f28e1128d9 Relanding r368987 [AArch64] Change location of frame-record within callee-save area.
Changes:
There was a condition for `!NeedsFrameRecord` missing in the assert. The
assert in question has changed to:

+    assert((!RPI.isPaired() || !NeedsFrameRecord || RPI.Reg2 != AArch64::FP ||
+            RPI.Reg1 == AArch64::LR) &&
+           "FrameRecord must be allocated together with LR");

This addresses PR43016.

llvm-svn: 369122
2019-08-16 15:42:28 +00:00
Nico Weber ee96499a42 Revert r368987, it caused PR43016.
llvm-svn: 369080
2019-08-16 02:21:21 +00:00
Sander de Smalen 643adb5576 [AArch64] Change location of frame-record within callee-save area.
This patch changes the location of the frame-record (FP, LR) to the 
bottom of the callee-saved area. According to the AAPCS the location of
the frame-record within the stackframe is unspecified (section 5.2.3 The 
Frame Pointer), so the compiler should be free to choose a different
location.

The reason for changing the location of the frame-record is to prepare
the frame for allocating an SVE area below the callee-saves. This way the 
compiler can use the VL-scaled addressing modes to directly access SVE 
objects from the frame-pointer.

            :                :   
        | stack |        | stack |
        |  args |        |  args |
        +-------+        +-------+
        |  x30  |        |  x19  |
        |  x29  |        |  x20  |
  FP -> |- - - -|        |  x21  |
        |  x19  |   ==>  |  x22  |
        |  x20  |        |- - - -|
        |  x21  |        |  x30  |
        |  x22  |        |  x29  |
        +-------+        +-------+ <- FP
        |///////|        |///////|         // realignment gap 
        |- - - -|        |- - - -|
        |spills/|        |spills/|
        | locals|        | locals|
  SP -> +-------+        +-------+ <- SP

Things to point out:
- The algorithm to find a paired register should be prevented from
  accidentally pairing some callee-saved register with LR that is not 
  FP, since they should always be paired together when the frame
  has a frame-record.
- For Darwin platforms the location of the frame-record is unchanged,
  since the unwind encoding does not allow for encoding this position
  dynamically and other tools currently depend on the former layout. 

Reviewers: efriedma, rovka, rengolin, thegameg, greened, t.p.northover

Reviewed By: efriedma

Differential Revision: https://reviews.llvm.org/D65653

llvm-svn: 368987
2019-08-15 10:34:16 +00:00
Sander de Smalen 5d6ee76c16 Describe stack-id as an enum
This patch changes MIR stack-id from an integer to an enum,
and adds printing/parsing support for this in MIR files. The default
stack-id '0' is now renamed to 'default'.

This should make MIR tests that have stack objects with different stack-ids
more descriptive. It also clarifies code operating on StackID.

Reviewers: arsenm, thegameg, qcolombet

Reviewed By: arsenm

Differential Revision: https://reviews.llvm.org/D60137

llvm-svn: 363533
2019-06-17 09:13:29 +00:00
Francis Visoiu Mistrih c855e92ca9 [AArch64] Place the first ldp at the end when ReverseCSRRestoreSeq is true
Put the first ldp at the end, so that the load-store optimizer can run
and merge the ldp and the add into a post-index ldp.

This didn't work in case no frame was needed and resulted in code size
regressions.

llvm-svn: 331044
2018-04-27 15:30:54 +00:00
Francis Visoiu Mistrih 57fcd3454a [MIR] Add support for debug metadata for fixed stack objects
Debug var, expr and loc were only supported for non-fixed stack objects.

This patch adds the following fields to the "fixedStack:" entries, and
renames the ones from "stack:" to:

* debug-info-variable
* debug-info-expression
* debug-info-location

Differential Revision: https://reviews.llvm.org/D46032

llvm-svn: 330859
2018-04-25 18:58:06 +00:00
Francis Visoiu Mistrih 164560bd74 [AArch64] Emit CSR loads in the same order as stores
Optionally allow the order of restoring the callee-saved registers in the
epilogue to be reversed.

The flag -reverse-csr-restore-seq generates the following code:

```
stp     x26, x25, [sp, #-64]!
stp     x24, x23, [sp, #16]
stp     x22, x21, [sp, #32]
stp     x20, x19, [sp, #48]

; [..]

ldp     x24, x23, [sp, #16]
ldp     x22, x21, [sp, #32]
ldp     x20, x19, [sp, #48]
ldp     x26, x25, [sp], #64
ret
```

Note how the CSRs are restored in the same order as they are saved.

One exception to this rule is the last `ldp`, which allows us to merge
the stack adjustment and the ldp into a post-index ldp. This is done by
first generating:

ldp x26, x27, [sp]
add sp, sp, #64

which gets merged by the arm64 load store optimizer into

ldp x26, x25, [sp], #64

The flag is disabled by default.

llvm-svn: 327569
2018-03-14 20:34:03 +00:00