Commit Graph

7 Commits

Author SHA1 Message Date
Dylan McKay 3c82c57d2b [AVR] Fix the 'load.ll' test after r362351
In that commit, the 'load.ll' test was modified, but still failed.

This commit updates the test so that it now passes.

llvm-svn: 362684
2019-06-06 08:06:50 +00:00
Jim Lin 20b14dacbb [AVR] Fix incorrect source regclass of LDWRdPtr
Summary:
LDWRdPtr would be expanded to ld+ldd. ldd only accepts the pointer register is Y or Z.
So the register class of pointer of LDWRdPtr should be PTRDISPREGS instead of PTRREGS.

Reviewers: dylanmckay

Reviewed By: dylanmckay

Subscribers: dylanmckay, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D62300

llvm-svn: 362351
2019-06-03 02:31:07 +00:00
Dylan McKay 6afef286d9 [AVR] Fix codegen bug in 16-bit loads
Prior to this patch, the AVR::LDWRdPtr instruction was always lowered to
instructions of this pattern:

    ld  $GPR8, [PTR:XYZ]+
    ld  $GPR8, [PTR]+1

This has a problem; the [PTR] is incremented in-place once, but never
decremented.

Future uses of the same pointer will use the now clobbered value,
leading to the pointer being incorrect by an offset of one.

This patch modifies the expansion code of the LDWRdPtr pseudo
instruction so that the pointer variable is not silently clobbered in
future uses in the same live range.

Bug first reported by Keshav Kini.

Patch by Kaushik Phatak.

llvm-svn: 351673
2019-01-20 03:41:08 +00:00
Dylan McKay 52846ab09a Revert "[AVR] Fix codegen bug in 16-bit loads"
This reverts commit r351544.

In that commit, I had mistakenly misattributed the issue submitter as
the patch author, Kaushik Phatak.

The patch will be recommitted immediately with the correct attribution.

llvm-svn: 351672
2019-01-20 03:41:00 +00:00
Dylan McKay 77364be497 [AVR] Fix codegen bug in 16-bit loads
Prior to this patch, the AVR::LDWRdPtr instruction was always lowered to
instructions of this pattern:

    ld  $GPR8, [PTR:XYZ]+
    ld  $GPR8, [PTR]+1

This has a problem; the [PTR] is incremented in-place once, but never
decremented.

Future uses of the same pointer will use the now clobbered value,
leading to the pointer being incorrect by an offset of one.

This patch modifies the expansion code of the LDWRdPtr pseudo
instruction so that the pointer variable is not silently clobbered in
future uses in the same live range.

Patch by Keshav Kini.

llvm-svn: 351544
2019-01-18 11:27:38 +00:00
Dylan McKay d00f9c1ef1 [AVR] Elaborate LDWRdPtr into `ld r, X++; ld r+1, X`
Patch by Gergo Erdi.

llvm-svn: 314896
2017-10-04 10:33:36 +00:00
Dylan McKay a789f40002 [AVR] Add the pseudo instruction expansion pass
Summary:
A lot of the pseudo instructions are required because LLVM assumes that
all integers of the same size as the pointer size are legal. This means
that it will not currently expand 16-bit instructions to their 8-bit
variants because it thinks 16-bit types are legal for the operations.

This also adds all of the CodeGen tests that required the pass to run.

Reviewers: arsenm, kparzysz

Subscribers: wdng, mgorny, modocache, llvm-commits

Differential Revision: https://reviews.llvm.org/D26577

llvm-svn: 287162
2016-11-16 21:58:04 +00:00