llvm/test/CodeGen/ARM/readcyclecounter.ll
Tim Northover 5a02fc4b5f ARM: implement @llvm.readcyclecounter intrinsic
This implements the @llvm.readcyclecounter intrinsic as the specific
MRC instruction specified in the ARM manuals for CPUs with the Power
Management extensions.

Older CPUs had slightly different methods which may also have to be
implemented eventually, but this should cover all v7 cases.

rdar://problem/13939186

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@182603 91177308-0d34-0410-b5e6-96231b3b80d8
2013-05-23 19:11:20 +00:00

25 lines
924 B
LLVM

; RUN: llc -mtriple=armv7-none-linux-gnueabi < %s | FileCheck %s
; RUN: llc -mtriple=thumbv7-none-linux-gnueabi < %s | FileCheck %s
; RUN: llc -mtriple=armv7-none-linux-gnueabi -mattr=-perfmon < %s | FileCheck %s --check-prefix=CHECK-NO-PERFMON
; RUN: llc -mtriple=armv6-none-linux-gnueabi < %s | FileCheck %s --check-prefix=CHECK-NO-PERFMON
; The performance monitor we're looking for is an ARMv7 extension. It should be
; possible to disable it, but realistically present on at least every v7-A
; processor (but not on v6, at least by default).
declare i64 @llvm.readcyclecounter()
define i64 @get_count() {
%val = call i64 @llvm.readcyclecounter()
ret i64 %val
; As usual, exact registers only sort of matter but the cycle-count had better
; end up in r0 in the end.
; CHECK: mrc p15, #0, r0, c9, c13, #0
; CHECK: {{movs?}} r1, #0
; CHECK-NO-PERFMON: {{movs?}} r0, #0
; CHECK-NO-PERFMON: {{movs?}} r1, #0
}