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llvm-project/llvm/test/CodeGen/ARM/cortex-a57-misched-vstm.ll

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[ARM] Cortex-A57 scheduling model for ARM backend (AArch32) This patch implements the Cortex-A57 scheduling model. The main code is in ARMScheduleA57.td, ARMScheduleA57WriteRes.td. Small changes in cpp,.h files to support required scheduling predicates. Scheduling model implemented according to: http://infocenter.arm.com/help/topic/com.arm.doc.uan0015b/Cortex_A57_Software_Optimization_Guide_external.pdf. Patch by : Andrew Zhogin (submitted on his behalf, as requested). Rewiewed by: Renato Golin, Diana Picus, Javed Absar, Kristof Beyls. Differential Revision: https://reviews.llvm.org/D28152 llvm-svn: 304530
2017-06-02 16:53:19 +08:00
; REQUIRES: asserts
[Scheduling][ARM] Consistently enable PostRA Machine scheduling In the ARM backend, for historical reasons we have only some targets using Machine Scheduling. The rest use the old list scheduler as they are using itinaries and the list scheduler seems to produce better code (and not crash running out of register on v6m codes). So whether to use the MIScheduler or not is checked at runtime from the subtarget features. This is fine, except for post-ra scheduling. Whether to use the old post-ra list scheduler or the post-ra machine schedule is decided as the pass manager is set up, in arms case from a newly constructed subtarget. Under some situations, like LTO, this won't include the correct cpu so can pick the wrong option. This can have a surprising effect on performance. To fix that, this patch overrides targetSchedulesPostRAScheduling and addPreSched2 in the ARM backend, adding _both_ post-ra schedulers and picking at runtime which to execute. To pick between the two I've had to add a enablePostRAMachineScheduler() method that normally returns enableMachineScheduler() && enablePostRAScheduler(), which can be overridden to enable just one of PostRAMachineScheduler vs PostRAScheduler. Thanks to David Penry for the identifying this problem. Differential Revision: https://reviews.llvm.org/D69775
2019-11-05 17:10:58 +08:00
; RUN: llc < %s -mtriple=armv8r-eabi -mcpu=cortex-a57 -mattr=use-misched -verify-misched -debug-only=machine-scheduler -o - 2>&1 > /dev/null | FileCheck %s
[ARM] Cortex-A57 scheduling model for ARM backend (AArch32) This patch implements the Cortex-A57 scheduling model. The main code is in ARMScheduleA57.td, ARMScheduleA57WriteRes.td. Small changes in cpp,.h files to support required scheduling predicates. Scheduling model implemented according to: http://infocenter.arm.com/help/topic/com.arm.doc.uan0015b/Cortex_A57_Software_Optimization_Guide_external.pdf. Patch by : Andrew Zhogin (submitted on his behalf, as requested). Rewiewed by: Renato Golin, Diana Picus, Javed Absar, Kristof Beyls. Differential Revision: https://reviews.llvm.org/D28152 llvm-svn: 304530
2017-06-02 16:53:19 +08:00
; CHECK: ********** MI Scheduling **********
; We need second, post-ra scheduling to have VSTM instruction combined from single-stores
; CHECK: ********** MI Scheduling **********
; CHECK: schedule starting
; CHECK: VSTMDIA
; CHECK: rdefs left
; CHECK-NEXT: Latency : 2
%bigVec = type [2 x double]
@var = global %bigVec zeroinitializer
define void @bar(%bigVec* %ptr) {
%tmp = load %bigVec, %bigVec* %ptr
store %bigVec %tmp, %bigVec* @var
ret void
}