[AArch64] This is a work in progress to provide a machine description

for the Cortex-A53 subtarget in the AArch64 backend.

This patch lays the ground work to annotate each AArch64 instruction
(no NEON yet) with a list of SchedReadWrite types. The patch also
provides the Cortex-A53 processor resources, maps those the the default
SchedReadWrites, and provides basic latency. NEON support will be added
in a subsequent patch with proper forwarding logic.

Verification was done by setting the pre-RA scheduler to linearize to
better gauge the effect of the MIScheduler. Even without modeling the
forward logic, the results show a modest improvement for Cortex-A53.

Reviewers: apazos, mcrosier, atrick
Patch by Dave Estes <cestes@codeaurora.org>!

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@202767 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 83 insertions, 0 deletions

diff --git a/test/CodeGen/AArch64/misched-basic-A53.ll b/test/CodeGen/AArch64/misched-basic-A53.ll
new file mode 100644
index 0000000000..24dd673fdb
--- /dev/null
+++ b/test/CodeGen/AArch64/misched-basic-A53.ll
@@ -0,0 +1,83 @@
+; REQUIRES: asserts
+; RUN: llc < %s -march=aarch64 -mcpu=cortex-a53 -pre-RA-sched=source -enable-misched -verify-misched -debug-only=misched -o - 2>&1 > /dev/null | FileCheck %s
+;
+; The Cortex-A53 machine model will cause the MADD instruction to be scheduled
+; much higher than the ADD instructions in order to hide latency. When not
+; specifying a subtarget, the MADD will remain near the end of the block.
+; CHECK: main
+; CHECK: *** Final schedule for BB#2 ***
+; CHECK: SU(13)
+; CHECK: MADDwwww
+; CHECK: SU(4)
+; CHECK: ADDwwi_lsl0_s
+; CHECK: ********** MI Scheduling **********
+@main.x = private unnamed_addr constant [8 x i32] [i32 1, i32 1, i32 1, i32 1, i32 1, i32 1, i32 1, i32 1], align 4
+@main.y = private unnamed_addr constant [8 x i32] [i32 2, i32 2, i32 2, i32 2, i32 2, i32 2, i32 2, i32 2], align 4
+
+; Function Attrs: nounwind
+define i32 @main() #0 {
+entry:
+  %retval = alloca i32, align 4
+  %x = alloca [8 x i32], align 4
+  %y = alloca [8 x i32], align 4
+  %i = alloca i32, align 4
+  %xx = alloca i32, align 4
+  %yy = alloca i32, align 4
+  store i32 0, i32* %retval
+  %0 = bitcast [8 x i32]* %x to i8*
+  call void @llvm.memcpy.p0i8.p0i8.i64(i8* %0, i8* bitcast ([8 x i32]* @main.x to i8*), i64 32, i32 4, i1 false)
+  %1 = bitcast [8 x i32]* %y to i8*
+  call void @llvm.memcpy.p0i8.p0i8.i64(i8* %1, i8* bitcast ([8 x i32]* @main.y to i8*), i64 32, i32 4, i1 false)
+  store i32 0, i32* %xx, align 4
+  store i32 0, i32* %yy, align 4
+  store i32 0, i32* %i, align 4
+  br label %for.cond
+
+for.cond:                                         ; preds = %for.inc, %entry
+  %2 = load i32* %i, align 4
+  %cmp = icmp slt i32 %2, 8
+  br i1 %cmp, label %for.body, label %for.end
+
+for.body:                                         ; preds = %for.cond
+  %3 = load i32* %i, align 4
+  %idxprom = sext i32 %3 to i64
+  %arrayidx = getelementptr inbounds [8 x i32]* %x, i32 0, i64 %idxprom
+  %4 = load i32* %arrayidx, align 4
+  %add = add nsw i32 %4, 1
+  store i32 %add, i32* %xx, align 4
+  %5 = load i32* %xx, align 4
+  %add1 = add nsw i32 %5, 12
+  store i32 %add1, i32* %xx, align 4
+  %6 = load i32* %xx, align 4
+  %add2 = add nsw i32 %6, 23
+  store i32 %add2, i32* %xx, align 4
+  %7 = load i32* %xx, align 4
+  %add3 = add nsw i32 %7, 34
+  store i32 %add3, i32* %xx, align 4
+  %8 = load i32* %i, align 4
+  %idxprom4 = sext i32 %8 to i64
+  %arrayidx5 = getelementptr inbounds [8 x i32]* %y, i32 0, i64 %idxprom4
+  %9 = load i32* %arrayidx5, align 4
+  %10 = load i32* %yy, align 4
+  %mul = mul nsw i32 %10, %9
+  store i32 %mul, i32* %yy, align 4
+  br label %for.inc
+
+for.inc:                                          ; preds = %for.body
+  %11 = load i32* %i, align 4
+  %inc = add nsw i32 %11, 1
+  store i32 %inc, i32* %i, align 4
+  br label %for.cond
+
+for.end:                                          ; preds = %for.cond
+  %12 = load i32* %xx, align 4
+  %13 = load i32* %yy, align 4
+  %add6 = add nsw i32 %12, %13
+  ret i32 %add6
+}
+
+; Function Attrs: nounwind
+declare void @llvm.memcpy.p0i8.p0i8.i64(i8* nocapture, i8* nocapture readonly, i64, i32, i1) #1
+
+attributes #0 = { nounwind "less-precise-fpmad"="false" "no-frame-pointer-elim"="true" "no-frame-pointer-elim-non-leaf" "no-infs-fp-math"="false" "no-nans-fp-math"="false" "stack-protector-buffer-size"="8" "unsafe-fp-math"="false" "use-soft-float"="false" }
+attributes #1 = { nounwind }