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
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
Summary:
Direct sibling of D62662, the root cause of the endless combine loop in D62257
https://rise4fun.com/Alive/d3W
Reviewers: RKSimon, craig.topper, spatel, t.p.northover
Reviewed By: t.p.northover
Subscribers: t.p.northover, javed.absar, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D62664
llvm-svn: 362133
Summary:
This was the root cause of the endless combine loop in D62257
https://rise4fun.com/Alive/d3W
Reviewers: RKSimon, spatel, craig.topper, t.p.northover
Reviewed By: t.p.northover
Subscribers: t.p.northover, javed.absar, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D62662
llvm-svn: 362131
This adds hopefully-full test coverage for all the possible permutations:
First op is one of:
* x + c1
* x - c1
* c1 - x
Second op is one of:
* + c2
* - c2
* c2 -
And thus 3*3=9 patterns.
Some of them show missed constant-folds.
Without previous patch (the revert), these tests were causing endless
dagcombine loop. I really should have thought about this first :S
llvm-svn: 362110
Sander de Smalen