This commit implements an IR-level optimization to eliminate idempotent
SVE mul/fmul intrinsic calls. Currently, the following patterns are
captured:
fmul pg (dup_x 1.0) V => V
mul pg (dup_x 1) V => V
fmul pg V (dup_x 1.0) => V
mul pg V (dup_x 1) => V
fmul pg V (dup v pg 1.0) => V
mul pg V (dup v pg 1) => V
The result of this commit is that code such as:
1 #include <arm_sve.h>
2
3 svfloat64_t foo(svfloat64_t a) {
4 svbool_t t = svptrue_b64();
5 svfloat64_t b = svdup_f64(1.0);
6 return svmul_m(t, a, b);
7 }
will lower to a nop.
This commit does not capture all possibilities; only the simple cases
described above. There is still room for further optimisation.
Differential Revision: https://reviews.llvm.org/D98033
It is possible to eliminate redundant calls to the SVE ptrue intrinsic.
For example: suppose that we have two SVE ptrue intrinsic calls P1 and
P2. If P1 is at least as wide as P2, then P2 can be written as a
reinterpret P1 using the SVE reinterpret intrinsics.
Coalescing ptrue intrinsics can result in fewer ptrue instructions in
the codegen, and is conducive to better analysis further down the line.
This commit extends the aarch64-sve-intrinsic-opts pass to support
coalescing ptrue intrisic calls.
Reviewed By: david-arm
Differential Revision: https://reviews.llvm.org/D94230
This commit extends SVEIntrinsicOpts::optimizeConvertFromSVBool to
identify and remove longer chains of redundant SVE reintepret
intrinsics. For example, the following chain of redundant SVE
reinterprets is now recognised as redundant:
%a = <vscale x 2 x i1>
%1 = <vscale x 16 x i1> @llvm.aarch64.sve.convert.to.svbool(<vscale x 2 x i1> %a)
%2 = <vscale x 4 x i1> @llvm.aarch64.sve.convert.from.svbool(<vscale x 16 x i1> %1)
%3 = <vscale x 16 x i1> @llvm.aarch64.sve.convert.to.svbool(<vscale x 4 x i1> %2)
%4 = <vscale x 4 x i1> @llvm.aarch64.sve.convert.from.svbool(<vscale x 16 x i1> %3)
%5 = <vscale x 16 x i1> @llvm.aarch64.sve.convert.to.svbool(<vscale x 4 x i1> %4)
%6 = <vscale x 2 x i1> @llvm.aarch64.sve.convert.from.svbool(<vscale x 16 x i1> %5)
ret <vscale x 2 x i1> %6
and will be replaced with:
ret <vscale x 2 x i1> %a
Eliminating these can sometimes mean emitting fewer unnecessary
loads/stores when lowering to assembly.
Differential Revision: https://reviews.llvm.org/D94074
Don't directly dereference a dyn_cast<> - use cast<> so we assert for the correct type.
Also, simplify the for loop to a range loop.
Fixes clang static analyzer warning.
The code wasn't taking into account that the two operands
passed to ptest could be identical and was trying to erase
them twice.
Differential Revision: https://reviews.llvm.org/D85892
Summary:
Creates the SVEIntrinsicOpts pass. In this patch, the pass tries
to remove unnecessary reinterpret intrinsics which convert to
and from svbool_t (llvm.aarch64.sve.convert.[to|from].svbool)
For example, the reinterprets below are redundant:
%1 = call <vscale x 16 x i1> @llvm.aarch64.sve.convert.to.svbool.nxv4i1(<vscale x 4 x i1> %a)
%2 = call <vscale x 4 x i1> @llvm.aarch64.sve.convert.from.svbool.nxv4i1(<vscale x 16 x i1> %1)
The pass also looks for ptest intrinsics and phi instructions where
the operands are being needlessly converted to and from svbool_t.
Reviewers: sdesmalen, andwar, efriedma, cameron.mcinally, c-rhodes, rengolin
Reviewed By: efriedma
Subscribers: mgorny, tschuett, kristof.beyls, hiraditya, rkruppe, psnobl, danielkiss, cfe-commits, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D76078
Joe Ellis