17 Commits

Author SHA1 Message Date
Tim Northover
2eb18d3c4b GlobalISel: fix legalization of G_INSERT
We were calculating incorrect extract/insert offsets by trying to be too
tricksy with min/max. It's clearer to just split the logic up into "register
starts before this segment" vs "after".

llvm-svn: 297226
2017-03-07 21:24:33 +00:00
Tim Northover
c2c545b8f7 GlobalISel: restrict G_EXTRACT instruction to just one operand.
A bit more painful than G_INSERT because it was more widely used, but this
should simplify the handling of extract operations in most locations.

llvm-svn: 297100
2017-03-06 23:50:28 +00:00
Tim Northover
75e0b91e59 GlobalISel: refactor legalization of G_INSERT.
Now that G_INSERT instructions can only insert one register, this code was
overly general. In another direction it didn't handle registers that crossed
split boundaries properly, which needed to be fixed.

llvm-svn: 297042
2017-03-06 18:23:04 +00:00
Tim Northover
bf017293af GlobalISel: add merge/unmerge nodes for legalization.
These are simplified variants of the current G_SEQUENCE and G_EXTRACT, which
assume the individual parts will be contiguous, homogeneous, and occupy the
entirity of the larger register. This makes reasoning about them much easer
since you only have to look at the first register being merged and the result
to know what the instruction is doing.

I intend to gradually replace all uses of the more complicated sequence/extract
with these (or single-element insert/extracts), and then remove the older
variants. For now we start with legalization.

llvm-svn: 296921
2017-03-03 22:46:09 +00:00
Tim Northover
9136617a3f GlobalISel: legalize va_arg on AArch64.
Uses a Custom implementation because the slot sizes being a multiple of the
pointer size isn't really universal, even for the architectures that do have a
simple "void *" va_list.

llvm-svn: 295255
2017-02-15 23:22:50 +00:00
Tim Northover
e041841811 GlobalISel: legalize G_FPOW to a libcall on AArch64.
There's no instruction to implement it.

llvm-svn: 294531
2017-02-08 23:23:39 +00:00
Tim Northover
0a9b27933a GlobalISel: expand mul-with-overflow into mul-hi on AArch64.
AArch64 has specific instructions to multiply two numbers at double the width
and produce the high part of the result. These can be used to implement LLVM's
mul.with.overflow instructions fairly simply. Helps with C++ operator new[].

llvm-svn: 294519
2017-02-08 21:22:15 +00:00
Tim Northover
868332d6bf GlobalISel: legalize narrow G_SELECTS on AArch64.
Otherwise there aren't any patterns to select them.

llvm-svn: 294261
2017-02-06 23:41:27 +00:00
Tim Northover
0e6afbdd77 GlobalISel: legalize G_INSERT instructions
We don't handle all cases yet (see arm64-fallback.ll for an example), but this
is enough to cover most common C++ code so it's a good place to start.

llvm-svn: 294247
2017-02-06 21:56:47 +00:00
Ahmed Bougacha
b6137063eb [AArch64][GlobalISel] Legalize narrow scalar fp->int conversions.
Since we're now avoiding operations using narrow scalar integer types,
we have to legalize the integer side of the FP conversions.

This requires teaching the legalizer how to do that.

llvm-svn: 292828
2017-01-23 21:10:14 +00:00
Ahmed Bougacha
d294823930 [AArch64][GlobalISel] Widen scalar int->fp conversions.
It's incorrect to ignore the higher bits of the integer source.
Teach the legalizer how to widen it.

llvm-svn: 292563
2017-01-20 01:37:24 +00:00
Justin Bogner
e094cc4372 GlobalISel: Add a note about how we're being a bit loose with memory operands
The logic in r292461 is conservatively correct, but we should revisit
this later. Add a TODO so we don't forget.

llvm-svn: 292553
2017-01-20 00:30:17 +00:00
Justin Bogner
ddb80aee7e GlobalISel: Implement widening for shifts
llvm-svn: 292476
2017-01-19 07:51:17 +00:00
Justin Bogner
d09c3ce6c0 GlobalISel: Implement narrowing for G_LOAD
llvm-svn: 292461
2017-01-19 01:05:48 +00:00
Justin Bogner
fde0104649 GlobalISel: Implement narrowing for G_STORE
Legalize stores of types that are too wide by breaking them up into
sequences of smaller stores.

llvm-svn: 292412
2017-01-18 17:29:54 +00:00
Tim Northover
9267ac5d47 GlobalISel: make G_CONSTANT take a ConstantInt rather than int64_t.
This makes it more similar to the floating-point constant, and also allows for
larger constants to be translated later. There's no real functional change in
this patch though, just syntax updates.

llvm-svn: 288712
2016-12-05 21:47:07 +00:00
Tim Northover
69fa84a6e9 GlobalISel: rename legalizer components to match others.
The previous names were both misleading (the MachineLegalizer actually
contained the info tables) and inconsistent with the selector & translator (in
having a "Machine") prefix. This should make everything sensible again.

The only functional change is the name of a couple of command-line options.

llvm-svn: 284287
2016-10-14 22:18:18 +00:00