Commit Graph

4 Commits

Author SHA1 Message Date
Alex Bradbury 8a70468a27 [RISCV] Only mark fp as reserved if the function has a dedicated frame pointer
This follows similar logic in the ARM and Mips backends, and allows the free
use of s0 in functions without a dedicated frame pointer. The changes in
callee-saved-gprs.ll most clearly show the effect of this patch.

llvm-svn: 356063
2019-03-13 16:33:45 +00:00
Alex Bradbury 32b77383ec [SelectionDAG] Support promotion of the FPOWI integer operand
For targets where i32 is not a legal type (e.g. 64-bit RISC-V),
LegalizeIntegerTypes must promote the integer operand of ISD::FPOWI. As this
is a signed value, this should be sign-extended.

This patch enables all tests in test/CodeGen/RISCVfloat-intrinsics.ll for
RV64, as prior to this patch that file couldn't be compiled for RV64 due to an
assertion when performing codegen for fpowi.

Differential Revision: https://reviews.llvm.org/D54574

llvm-svn: 352832
2019-02-01 03:46:28 +00:00
Alex Bradbury 919f5fb8ca [RISCV] Add support for the various RISC-V FMA instruction variants
Adds support for the various RISC-V FMA instructions (fmadd, fmsub, fnmsub, fnmadd).

The criteria for choosing whether a fused add or subtract is used, as well as
whether the product is negated or not, is whether some of the arguments to the
llvm.fma.* intrinsic are negated or not. In the tests, extraneous fadd
instructions were added to avoid the negation being performed using a xor
trick, which prevented the proper FMA forms from being selected and thus
tested.

The FMA instruction patterns might seem incorrect (e.g., fnmadd: -rs1 * rs2 -
rs3), but they should be correct. The misleading names were inherited from
MIPS, where the negation happens after computing the sum.

The llvm.fmuladd.* intrinsics still do not generate RISC-V FMA instructions,
as that depends on TargetLowering::isFMAFasterthanFMulAndFAdd.

Some comments in the test files about what type of instructions are there
tested were updated, to better reflect the current content of those test
files.

Differential Revision: https://reviews.llvm.org/D54205
Patch by Luís Marques.

llvm-svn: 349023
2018-12-13 10:49:05 +00:00
Alex Bradbury 52c27785ce [RISCV] Add some missing expansions for floating-point intrinsics
A number of intrinsics, such as llvm.sin.f32, would result in a failure to 
select. This patch adds expansions for the relevant selection DAG nodes, as 
well as exhaustive testing for all f32 and f64 intrinsics.

The codegen for FMA remains a TODO item, pending support for the various 
RISC-V FMA instruction variants.

The llvm.minimum.f32.* and llvm.maximum.* tests are commented-out, pending 
upstream support for target-independent expansion, as discussed in 
http://lists.llvm.org/pipermail/llvm-dev/2018-November/127408.html.

Differential Revision: https://reviews.llvm.org/D54034
Patch by Luís Marques.

llvm-svn: 346034
2018-11-02 19:50:38 +00:00