Add AArch64 as an experimental target.

This patch adds support for AArch64 (ARM's 64-bit architecture) to
LLVM in the "experimental" category. Currently, it won't be built
unless requested explicitly.

This initial commit should have support for:
    + Assembly of all scalar (i.e. non-NEON, non-Crypto) instructions
      (except the late addition CRC instructions).
    + CodeGen features required for C++03 and C99.
    + Compilation for the "small" memory model: code+static data <
      4GB.
    + Absolute and position-independent code.
    + GNU-style (i.e. "__thread") TLS.
    + Debugging information.

The principal omission, currently, is performance tuning.

This patch excludes the NEON support also reviewed due to an outbreak of
batshit insanity in our legal department. That will be committed soon bringing
the changes to precisely what has been approved.

Further reviews would be gratefully received.

llvm-svn: 174054

1 files changed, 117 insertions, 0 deletions

diff --git a/llvm/test/CodeGen/AArch64/large-frame.ll b/llvm/test/CodeGen/AArch64/large-frame.ll
new file mode 100644
index 00000000000..e924461f871
--- /dev/null
+++ b/llvm/test/CodeGen/AArch64/large-frame.ll
@@ -0,0 +1,117 @@
+; RUN: llc -verify-machineinstrs -march=aarch64 < %s | FileCheck %s
+declare void @use_addr(i8*)
+
+@addr = global i8* null
+
+define void @test_bigframe() {
+; CHECK: test_bigframe:
+
+  %var1 = alloca i8, i32 20000000
+  %var2 = alloca i8, i32 16
+  %var3 = alloca i8, i32 20000000
+; CHECK: sub sp, sp, #496
+; CHECK: str x30, [sp, #488]
+; CHECK: ldr [[FRAMEOFFSET:x[0-9]+]], [[FRAMEOFFSET_CPI:.LCPI0_[0-9]+]]
+; CHECK: sub sp, sp, [[FRAMEOFFSET]]
+
+; CHECK: ldr [[VAR1OFFSET:x[0-9]+]], [[VAR1LOC_CPI:.LCPI0_[0-9]+]]
+; CHECK: add {{x[0-9]+}}, sp, [[VAR1OFFSET]]
+  store volatile i8* %var1, i8** @addr
+
+  %var1plus2 = getelementptr i8* %var1, i32 2
+  store volatile i8* %var1plus2, i8** @addr
+
+; CHECK: ldr [[VAR2OFFSET:x[0-9]+]], [[VAR2LOC_CPI:.LCPI0_[0-9]+]]
+; CHECK: add {{x[0-9]+}}, sp, [[VAR2OFFSET]]
+  store volatile i8* %var2, i8** @addr
+
+  %var2plus2 = getelementptr i8* %var2, i32 2
+  store volatile i8* %var2plus2, i8** @addr
+
+  store volatile i8* %var3, i8** @addr
+
+  %var3plus2 = getelementptr i8* %var3, i32 2
+  store volatile i8* %var3plus2, i8** @addr
+
+; CHECK: ldr [[FRAMEOFFSET:x[0-9]+]], [[FRAMEOFFSET_CPI]]
+; CHECK: add sp, sp, [[FRAMEOFFSET]]
+  ret void
+
+; CHECK: [[FRAMEOFFSET_CPI]]:
+; CHECK-NEXT: 39999536
+
+; CHECK: [[VAR1LOC_CPI]]:
+; CHECK-NEXT: 20000024
+
+; CHECK: [[VAR2LOC_CPI]]:
+; CHECK-NEXT: 20000008
+}
+
+define void @test_mediumframe() {
+; CHECK: test_mediumframe:
+  %var1 = alloca i8, i32 1000000
+  %var2 = alloca i8, i32 16
+  %var3 = alloca i8, i32 1000000
+; CHECK: sub sp, sp, #496
+; CHECK: str x30, [sp, #488]
+; CHECK: sub sp, sp, #688
+; CHECK-NEXT: sub sp, sp, #488, lsl #12
+
+  store volatile i8* %var1, i8** @addr
+; CHECK: add [[VAR1ADDR:x[0-9]+]], sp, #600
+; CHECK: add [[VAR1ADDR]], [[VAR1ADDR]], #244, lsl #12
+
+  %var1plus2 = getelementptr i8* %var1, i32 2
+  store volatile i8* %var1plus2, i8** @addr
+; CHECK: add [[VAR1PLUS2:x[0-9]+]], {{x[0-9]+}}, #2
+
+  store volatile i8* %var2, i8** @addr
+; CHECK: add [[VAR2ADDR:x[0-9]+]], sp, #584
+; CHECK: add [[VAR2ADDR]], [[VAR2ADDR]], #244, lsl #12
+
+  %var2plus2 = getelementptr i8* %var2, i32 2
+  store volatile i8* %var2plus2, i8** @addr
+; CHECK: add [[VAR2PLUS2:x[0-9]+]], {{x[0-9]+}}, #2
+
+  store volatile i8* %var3, i8** @addr
+
+  %var3plus2 = getelementptr i8* %var3, i32 2
+  store volatile i8* %var3plus2, i8** @addr
+
+; CHECK: add sp, sp, #688
+; CHECK: add sp, sp, #488, lsl #12
+; CHECK: ldr x30, [sp, #488]
+; CHECK: add sp, sp, #496
+  ret void
+}
+
+
+@bigspace = global [8 x i64] zeroinitializer
+
+; If temporary registers are allocated for adjustment, they should *not* clobber
+; argument registers.
+define void @test_tempallocation([8 x i64] %val) nounwind {
+; CHECK: test_tempallocation:
+  %var = alloca i8, i32 1000000
+; CHECK: sub sp, sp,
+
+; Make sure the prologue is reasonably efficient
+; CHECK-NEXT: stp x29, x30, [sp,
+; CHECK-NEXT: stp x25, x26, [sp,
+; CHECK-NEXT: stp x23, x24, [sp,
+; CHECK-NEXT: stp x21, x22, [sp,
+; CHECK-NEXT: stp x19, x20, [sp,
+
+; Make sure we don't trash an argument register
+; CHECK-NOT: ldr {{x[0-7]}}, .LCPI1
+; CHECK: sub sp, sp,
+
+; CHECK-NOT: ldr {{x[0-7]}}, .LCPI1
+
+; CHECK: bl use_addr
+  call void @use_addr(i8* %var)
+
+  store [8 x i64] %val, [8 x i64]* @bigspace
+  ret void
+; CHECK: ret
+}