llvm-mirror/test/CodeGen/AArch64/falkor-hwpf.ll
Geoff Berry 2bb37a1dab [AArch64][Falkor] Avoid HW prefetcher tag collisions (step 1)
Summary:
This patch is the first step in reducing HW prefetcher instruction tag
collisions in inner loops for Falkor.  It adds a pass that annotates IR
loads with metadata to indicate that they are known to be strided loads,
and adds a target lowering hook that translates this metadata to a
target-specific MachineMemOperand flag.

A follow on change will use this MachineMemOperand flag to re-write
instructions to reduce tag collisions.

Reviewers: mcrosier, t.p.northover

Subscribers: aemerson, rengolin, mgorny, javed.absar, kristof.beyls, llvm-commits

Differential Revision: https://reviews.llvm.org/D34963

llvm-svn: 308059
2017-07-14 21:44:12 +00:00

107 lines
2.7 KiB
LLVM

; RUN: opt < %s -S -falkor-hwpf-fix -mtriple aarch64 -mcpu=falkor | FileCheck %s
; RUN: opt < %s -S -falkor-hwpf-fix -mtriple aarch64 -mcpu=cortex-a57 | FileCheck %s --check-prefix=NOHWPF
; Check that strided access metadata is added to loads in inner loops when compiling for Falkor.
; CHECK-LABEL: @hwpf1(
; CHECK: load i32, i32* %gep, !falkor.strided.access !0
; CHECK: load i32, i32* %gep2, !falkor.strided.access !0
; NOHWPF-LABEL: @hwpf1(
; NOHWPF: load i32, i32* %gep{{$}}
; NOHWPF: load i32, i32* %gep2{{$}}
define void @hwpf1(i32* %p, i32* %p2) {
entry:
br label %loop
loop:
%iv = phi i32 [ 0, %entry ], [ %inc, %loop ]
%gep = getelementptr inbounds i32, i32* %p, i32 %iv
%load = load i32, i32* %gep
%gep2 = getelementptr inbounds i32, i32* %p2, i32 %iv
%load2 = load i32, i32* %gep2
%inc = add i32 %iv, 1
%exitcnd = icmp uge i32 %inc, 1024
br i1 %exitcnd, label %exit, label %loop
exit:
ret void
}
; Check that outer loop strided load isn't marked.
; CHECK-LABEL: @hwpf2(
; CHECK: load i32, i32* %gep, !falkor.strided.access !0
; CHECK: load i32, i32* %gep2{{$}}
; NOHWPF-LABEL: @hwpf2(
; NOHWPF: load i32, i32* %gep{{$}}
; NOHWPF: load i32, i32* %gep2{{$}}
define void @hwpf2(i32* %p) {
entry:
br label %loop1
loop1:
%iv1 = phi i32 [ 0, %entry ], [ %inc1, %loop1.latch ]
%outer.sum = phi i32 [ 0, %entry ], [ %sum, %loop1.latch ]
br label %loop2.header
loop2.header:
br label %loop2
loop2:
%iv2 = phi i32 [ 0, %loop2.header ], [ %inc2, %loop2 ]
%sum = phi i32 [ %outer.sum, %loop2.header ], [ %sum.inc, %loop2 ]
%gep = getelementptr inbounds i32, i32* %p, i32 %iv2
%load = load i32, i32* %gep
%sum.inc = add i32 %sum, %load
%inc2 = add i32 %iv2, 1
%exitcnd2 = icmp uge i32 %inc2, 1024
br i1 %exitcnd2, label %exit2, label %loop2
exit2:
%gep2 = getelementptr inbounds i32, i32* %p, i32 %iv1
%load2 = load i32, i32* %gep2
br label %loop1.latch
loop1.latch:
%inc1 = add i32 %iv1, 1
%exitcnd1 = icmp uge i32 %inc1, 1024
br i1 %exitcnd2, label %exit, label %loop1
exit:
ret void
}
; Check that non-strided load isn't marked.
; CHECK-LABEL: @hwpf3(
; CHECK: load i32, i32* %gep, !falkor.strided.access !0
; CHECK: load i32, i32* %gep2{{$}}
; NOHWPF-LABEL: @hwpf3(
; NOHWPF: load i32, i32* %gep{{$}}
; NOHWPF: load i32, i32* %gep2{{$}}
define void @hwpf3(i32* %p, i32* %p2) {
entry:
br label %loop
loop:
%iv = phi i32 [ 0, %entry ], [ %inc, %loop ]
%gep = getelementptr inbounds i32, i32* %p, i32 %iv
%load = load i32, i32* %gep
%gep2 = getelementptr inbounds i32, i32* %p2, i32 %load
%load2 = load i32, i32* %gep2
%inc = add i32 %iv, 1
%exitcnd = icmp uge i32 %inc, 1024
br i1 %exitcnd, label %exit, label %loop
exit:
ret void
}