Commit Graph

8 Commits

Author SHA1 Message Date
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
Francis Visoiu Mistrih 25528d6de7 [CodeGen] Unify MBB reference format in both MIR and debug output
As part of the unification of the debug format and the MIR format, print
MBB references as '%bb.5'.

The MIR printer prints the IR name of a MBB only for block definitions.

* find . \( -name "*.mir" -o -name "*.cpp" -o -name "*.h" -o -name "*.ll" \) -type f -print0 | xargs -0 sed -i '' -E 's/BB#" << ([a-zA-Z0-9_]+)->getNumber\(\)/" << printMBBReference(*\1)/g'
* find . \( -name "*.mir" -o -name "*.cpp" -o -name "*.h" -o -name "*.ll" \) -type f -print0 | xargs -0 sed -i '' -E 's/BB#" << ([a-zA-Z0-9_]+)\.getNumber\(\)/" << printMBBReference(\1)/g'
* find . \( -name "*.txt" -o -name "*.s" -o -name "*.mir" -o -name "*.cpp" -o -name "*.h" -o -name "*.ll" \) -type f -print0 | xargs -0 sed -i '' -E 's/BB#([0-9]+)/%bb.\1/g'
* grep -nr 'BB#' and fix

Differential Revision: https://reviews.llvm.org/D40422

llvm-svn: 319665
2017-12-04 17:18:51 +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 4f5002198b [AVR] Use the correct register classes for 16-bit atomic operations
llvm-svn: 311620
2017-08-24 00:14:38 +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
Dylan McKay 0d4778f841 [AVR] Add a selection of CodeGen tests
Summary: This adds all of the CodeGen tests which currently pass.

Reviewers: arsenm, kparzysz

Subscribers: japaric, wdng

Differential Revision: https://reviews.llvm.org/D26388

llvm-svn: 286418
2016-11-09 23:46:52 +00:00