llvm-project/llvm/test/CodeGen/X86/statepoint-stackmap-format.ll

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[Statepoints 3/4] Statepoint infrastructure for garbage collection: SelectionDAGBuilder This is the third patch in a small series. It contains the CodeGen support for lowering the gc.statepoint intrinsic sequences (223078) to the STATEPOINT pseudo machine instruction (223085). The change also includes the set of helper routines and classes for working with gc.statepoints, gc.relocates, and gc.results since the lowering code uses them. With this change, gc.statepoints should be functionally complete. The documentation will follow in the fourth change, and there will likely be some cleanup changes, but interested parties can start experimenting now. I'm not particularly happy with the amount of code or complexity involved with the lowering step, but at least it's fairly well isolated. The statepoint lowering code is split into it's own files and anyone not working on the statepoint support itself should be able to ignore it. During the lowering process, we currently spill aggressively to stack. This is not entirely ideal (and we have plans to do better), but it's functional, relatively straight forward, and matches closely the implementations of the patchpoint intrinsics. Most of the complexity comes from trying to keep relocated copies of values in the same stack slots across statepoints. Doing so avoids the insertion of pointless load and store instructions to reshuffle the stack. The current implementation isn't as effective as I'd like, but it is functional and 'good enough' for many common use cases. In the long term, I'd like to figure out how to integrate the statepoint lowering with the register allocator. In principal, we shouldn't need to eagerly spill at all. The register allocator should do any spilling required and the statepoint should simply record that fact. Depending on how challenging that turns out to be, we may invest in a smarter global stack slot assignment mechanism as a stop gap measure. Reviewed by: atrick, ributzka llvm-svn: 223137
2014-12-03 02:50:36 +08:00
; RUN: llc < %s | FileCheck %s
; This test is a sanity check to ensure statepoints are generating StackMap
; sections correctly. This is not intended to be a rigorous test of the
; StackMap format (see the stackmap tests for that).
target datalayout = "e-i64:64-f80:128-n8:16:32:64-S128"
target triple = "x86_64-pc-linux-gnu"
declare zeroext i1 @return_i1()
define i1 @test(i32 addrspace(1)* %ptr) {
; CHECK-LABEL: test
; Do we see one spill for the local value and the store to the
; alloca?
; CHECK: subq $24, %rsp
; CHECK: movq $0, 8(%rsp)
; CHECK: movq %rdi, (%rsp)
; CHECK: callq return_i1
; CHECK: addq $24, %rsp
; CHECK: retq
entry:
%metadata1 = alloca i32 addrspace(1)*, i32 2, align 8
store i32 addrspace(1)* null, i32 addrspace(1)** %metadata1
; NOTE: Currently NOT testing alloca lowering in the StackMap format. Its
; known to be broken.
%safepoint_token = tail call i32 (i1 ()*, i32, i32, ...)* @llvm.experimental.gc.statepoint.p0f_i1f(i1 ()* @return_i1, i32 0, i32 0, i32 2, i32 addrspace(1)* %ptr, i32 addrspace(1)* null)
%call1 = call zeroext i1 @llvm.experimental.gc.result.int.i1(i32 %safepoint_token)
%a = call i32 addrspace(1)* @llvm.experimental.gc.relocate.p1i32(i32 %safepoint_token, i32 4, i32 4)
%b = call i32 addrspace(1)* @llvm.experimental.gc.relocate.p1i32(i32 %safepoint_token, i32 5, i32 5)
;
ret i1 %call1
}
declare i32 @llvm.experimental.gc.statepoint.p0f_i1f(i1 ()*, i32, i32, ...)
declare i1 @llvm.experimental.gc.result.int.i1(i32)
declare i32 addrspace(1)* @llvm.experimental.gc.relocate.p1i32(i32, i32, i32) #3
; CHECK-LABEL: .section .llvm_stackmaps
; CHECK-NEXT: __LLVM_StackMaps:
; Header
; CHECK-NEXT: .byte 1
; CHECK-NEXT: .byte 0
; CHECK-NEXT: .short 0
; Num Functions
; CHECK-NEXT: .long 1
; Num LargeConstants
; CHECK-NEXT: .long 0
; Num Callsites
; CHECK-NEXT: .long 1
; Functions and stack size
; CHECK-NEXT: .quad test
; CHECK-NEXT: .quad 24
; Large Constants
; Statepoint ID only
; CHECK: .quad 2882400000
; Callsites
; Constant arguments
; CHECK: .long .Ltmp1-test
; CHECK: .short 0
; CHECK: .short 8
; SmallConstant (0)
; CHECK: .byte 4
; CHECK: .byte 8
; CHECK: .short 0
; CHECK: .long 0
; SmallConstant (2)
; CHECK: .byte 4
; CHECK: .byte 8
; CHECK: .short 0
; CHECK: .long 2
; Direct Spill Slot [RSP+0]
; CHECK: .byte 2
; CHECK: .byte 8
; CHECK: .short 7
; CHECK: .long 0
; SmallConstant (0)
; CHECK: .byte 4
; CHECK: .byte 8
; CHECK: .short 0
; CHECK: .long 0
; SmallConstant (0)
; CHECK: .byte 4
; CHECK: .byte 8
; CHECK: .short 0
; CHECK: .long 0
; SmallConstant (0)
; CHECK: .byte 4
; CHECK: .byte 8
; CHECK: .short 0
; CHECK: .long 0
; Direct Spill Slot [RSP+0]
; CHECK: .byte 2
; CHECK: .byte 8
; CHECK: .short 7
; CHECK: .long 0
; Direct Spill Slot [RSP+0]
; CHECK: .byte 2
; CHECK: .byte 8
; CHECK: .short 7
; CHECK: .long 0
; No Padding or LiveOuts
; CHECK: .short 0
; CHECK: .short 0
; CHECK: .align 8