llvm-6502

mirror of https://github.com/c64scene-ar/llvm-6502.git synced 2025-02-05 14:34:55 +00:00

History

Hal Finkel 19046ec19c Fix SCEVExpander creating distinct duplicate PHI entries

This fixes SCEVExpander so that it does not create multiple distinct induction
variables for duplicate PHI entries. Specifically, given some code like this:

do.body6:                                         ; preds = %do.body6, %do.body6, %if.then5
  %end.0 = phi i8* [ undef, %if.then5 ], [ %incdec.ptr, %do.body6 ], [ %incdec.ptr, %do.body6 ]
...

Note that it is legal to have multiple entries for a basic block so long as the
associated value is the same. So the above input is okay, but expanding an
AddRec in this loop could produce code like this:

do.body6:                                         ; preds = %do.body6, %do.body6, %if.then5
  %indvar = phi i64 [ %indvar.next, %do.body6 ], [ %indvar.next1, %do.body6 ], [ 0, %if.then5 ]
  %end.0 = phi i8* [ undef, %if.then5 ], [ %incdec.ptr, %do.body6 ], [ %incdec.ptr, %do.body6 ]
...
  %indvar.next = add i64 %indvar, 1
  %indvar.next1 = add i64 %indvar, 1

And this is not legal because there are two PHI entries for %do.body6 each with
a distinct value.

Unfortunately, I don't have an in-tree test case.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@188614 91177308-0d34-0410-b5e6-96231b3b80d8

2013-08-18 00:16:23 +00:00

Analysis

Fix SCEVExpander creating distinct duplicate PHI entries

2013-08-18 00:16:23 +00:00

AsmParser

…

Bitcode

Make .bc en/decoding of AttrKind stable

2013-07-26 04:16:55 +00:00

CodeGen

ARM: Fix more fast-isel verifier failures.

2013-08-16 23:37:31 +00:00