llvm/test/CodeGen/AArch64/readcyclecounter.ll
Ahmed Bougacha 37d12daa3a [AArch64] Lower READCYCLECOUNTER using MRS PMCCTNR_EL0.
This matches the ARM behavior. In both cases, the register is part
of the optional Performance Monitors extension, so, add the feature,
and enable it for the A-class processors we support.

Differential Revision: http://reviews.llvm.org/D12425



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@246555 91177308-0d34-0410-b5e6-96231b3b80d8
2015-09-01 16:23:45 +00:00

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578 B
LLVM

; RUN: llc -mtriple=aarch64-unknown-unknown -asm-verbose=false < %s |\
; RUN: FileCheck %s --check-prefix=CHECK --check-prefix=PERFMON
; RUN: llc -mtriple=aarch64-unknown-unknown -mattr=-perfmon -asm-verbose=false < %s |\
; RUN: FileCheck %s --check-prefix=CHECK --check-prefix=NOPERFMON
define i64 @test_readcyclecounter() nounwind {
; CHECK-LABEL: test_readcyclecounter:
; PERFMON-NEXT: mrs x0, PMCCNTR_EL0
; NOPERFMON-NEXT: mov x0, xzr
; CHECK-NEXT: ret
%tmp0 = call i64 @llvm.readcyclecounter()
ret i64 %tmp0
}
declare i64 @llvm.readcyclecounter()