Commit Graph

5 Commits

Author SHA1 Message Date
Lucas Prates 3d943bcd22 [CodeGen] Properly propagating Calling Convention information when lowering vector arguments
When joining the legal parts of vector arguments into its original value
during the lower of Formal Arguments in SelectionDAGBuilder, the Calling
Convention information was not being propagated for the handling of each
individual parts. The same did not happen when lowering calls, causing a
mismatch.

This patch fixes the issue by properly propagating the Calling
Convention details.

This fixes Bugzilla #47001.

Reviewed By: arsenm

Differential Revision: https://reviews.llvm.org/D86715
2020-08-27 17:01:10 +01:00
David Green 74ca67c109 [ARM] Remove hasSideEffects from FP converts
Whether an instruction is deemed to have side effects in determined by
whether it has a tblgen pattern that emits a single instruction.
Because of the way a lot of the the vcvt instructions are specified
either in dagtodag code or with patterns that emit multiple
instructions, they don't get marked as not having side effects.

This just marks them as not having side effects manually. It can help
especially with instruction scheduling, to not create artificial
barriers, but one of these tests also managed to produce fewer
instructions.

Differential Revision: https://reviews.llvm.org/D81639
2020-07-05 16:23:24 +01:00
Lucas Prates a255931c40 [ARM] Supporting lowering of half-precision FP arguments and returns in AArch32's backend
Summary:
Half-precision floating point arguments and returns are currently
promoted to either float or int32 in clang's CodeGen and there's
no existing support for the lowering of `half` arguments and returns
from IR in AArch32's backend.

Such frontend coercions, implemented as coercion through memory
in clang, can cause a series of issues in argument lowering, as causing
arguments to be stored on the wrong bits on big-endian architectures
and incurring in missing overflow detections in the return of certain
functions.

This patch introduces the handling of half-precision arguments and returns in
the backend using the actual "half" type on the IR. Using the "half"
type the backend is able to properly enforce the AAPCS' directions for
those arguments, making sure they are stored on the proper bits of the
registers and performing the necessary floating point convertions.

Reviewers: rjmccall, olista01, asl, efriedma, ostannard, SjoerdMeijer

Reviewed By: ostannard

Subscribers: stuij, hiraditya, dmgreen, llvm-commits, chill, dnsampaio, danielkiss, kristof.beyls, cfe-commits

Tags: #clang, #llvm

Differential Revision: https://reviews.llvm.org/D75169
2020-06-18 13:15:13 +01:00
Pirama Arumuga Nainar bf5ccdccb2 Do not ASSERTZEXT for i16 result of bitcast from f16 operand
Summary:
During legalization if i16, do not ASSERTZEXT the result of FP_TO_FP16.
Directly return an FP_TO_FP16 node with return type as the
promote-to-type of i16.

This patch also removes extraneous length check.  This legalization
should be valid even if integer and float types are of different
lengths.

This patch breaks a hard-float test for fp16 args.  The test is changed
to allow a vmov to zero-out the top bits, and also ensure that the
return value is in an FP register.

Reviewers: ab, jmolloy

Subscribers: srhines, llvm-commits

Differential Revision: http://reviews.llvm.org/D15438

llvm-svn: 257184
2016-01-08 17:46:05 +00:00
Oliver Stannard 284f2bffc9 Add DAG optimisation for FP16_TO_FP
The FP16_TO_FP node only uses the bottom 16 bits of its input, so the
following pattern can be optimised by removing the AND:

  (FP16_TO_FP (AND op, 0xffff)) -> (FP16_TO_FP op)

This is a common pattern for ARM targets when functions have __fp16
arguments, as they are passed as floats (so that they get passed in the
correct registers), but then bitcast and truncated to ignore the top 16
bits.

llvm-svn: 245832
2015-08-24 09:47:45 +00:00