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clang-p2996/llvm/test/CodeGen/X86/statepoint-vector.ll
Denis Antrushin c08d48fc2d [Statepoints] Change statepoint machine instr format to better suit VReg lowering. 
Current Statepoint MI format is this:

   STATEPOINT
   <id>, <num patch bytes >, <num call arguments>, <call target>,
   [call arguments...],
   <StackMaps::ConstantOp>, <calling convention>,
   <StackMaps::ConstantOp>, <statepoint flags>,
   <StackMaps::ConstantOp>, <num deopt args>, [deopt args...],
   <gc base/derived pairs...> <gc allocas...>

Note that GC pointers are listed in pairs <base,derived>.
This causes base pointers to appear many times (at least twice) in
instruction, which is bad for us when VReg lowering is ON.
The problem is that machine operand tiedness is 1-1 relation, so
it might look like this:

  %vr2 = STATEPOINT ... %vr1, %vr1(tied-def0)

Since only one instance of %vr1 is tied, that may lead to incorrect
codegen (see PR46917 for more details), so we have to always spill
base pointers. This mostly defeats new VReg lowering scheme.

This patch changes statepoint instruction format so that every
gc pointer appears only once in operand list. That way they all can
be tied. Additional set of operands is added to preserve base-derived
relation required to build stackmap.
New statepoint has following format:

  STATEPOINT
  <id>, <num patch bytes>, <num call arguments>, <call target>,
  [call arguments...],
  <StackMaps::ConstantOp>, <calling convention>,
  <StackMaps::ConstantOp>, <statepoint flags>,
  <StackMaps::ConstantOp>, <num deopt args>, [deopt args...],
  <StackMaps::ConstantOp>, <num gc pointers>, [gc pointers...],
  <StackMaps::ConstantOp>, <num gc allocas>,  [gc allocas...]
  <StackMaps::ConstantOp>, <num entries in gc map>, [base/derived indices...]

Changes are:
  - every gc pointer is listed only once in a flat length-prefixed list;
  - alloca list is prefixed with its length too;
  - following alloca list is length-prefixed list of base-derived
    indices of pointers from gc pointer list. Note that indices are
    logical (number of pointer), not absolute (index of machine operand).

Differential Revision: https://reviews.llvm.org/D87154
2020-10-06 17:40:29 +07:00

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; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py
; RUN: llc -verify-machineinstrs -stack-symbol-ordering=0 -mcpu=nehalem -debug-only=stackmaps < %s | FileCheck %s
; REQUIRES: asserts
target triple = "x86_64-pc-linux-gnu"
; Can we lower a single vector?
define <2 x i8 addrspace(1)*> @test(<2 x i8 addrspace(1)*> %obj) gc "statepoint-example" {
; CHECK-LABEL: test:
; CHECK: # %bb.0: # %entry
; CHECK-NEXT: subq $24, %rsp
; CHECK-NEXT: .cfi_def_cfa_offset 32
; CHECK-NEXT: movaps %xmm0, (%rsp)
; CHECK-NEXT: callq do_safepoint
; CHECK-NEXT: .Ltmp0:
; CHECK-NEXT: movaps (%rsp), %xmm0
; CHECK-NEXT: addq $24, %rsp
; CHECK-NEXT: .cfi_def_cfa_offset 8
; CHECK-NEXT: retq
entry:
%safepoint_token = call token (i64, i32, void ()*, i32, i32, ...) @llvm.experimental.gc.statepoint.p0f_isVoidf(i64 0, i32 0, void ()* @do_safepoint, i32 0, i32 0, i32 0, i32 0) ["gc-live" (<2 x i8 addrspace(1)*> %obj)]
%obj.relocated = call coldcc <2 x i8 addrspace(1)*> @llvm.experimental.gc.relocate.v2p1i8(token %safepoint_token, i32 0, i32 0) ; (%obj, %obj)
ret <2 x i8 addrspace(1)*> %obj.relocated
}
; Can we lower the base, derived pairs if both are vectors?
define <2 x i8 addrspace(1)*> @test2(<2 x i8 addrspace(1)*> %obj, i64 %offset) gc "statepoint-example" {
; CHECK-LABEL: test2:
; CHECK: # %bb.0: # %entry
; CHECK-NEXT: subq $40, %rsp
; CHECK-NEXT: .cfi_def_cfa_offset 48
; CHECK-NEXT: movq %rdi, %xmm1
; CHECK-NEXT: pshufd {{.*#+}} xmm1 = xmm1[0,1,0,1]
; CHECK-NEXT: paddq %xmm0, %xmm1
; CHECK-NEXT: movdqa %xmm0, {{[0-9]*}}(%rsp)
; CHECK-NEXT: movdqa %xmm1, {{[0-9]*}}(%rsp)
; CHECK-NEXT: callq do_safepoint
; CHECK-NEXT: .Ltmp1:
; CHECK-NEXT: movaps {{[0-9]*}}(%rsp), %xmm0
; CHECK-NEXT: addq $40, %rsp
; CHECK-NEXT: .cfi_def_cfa_offset 8
; CHECK-NEXT: retq
entry:
%derived = getelementptr i8, <2 x i8 addrspace(1)*> %obj, i64 %offset
%safepoint_token = call token (i64, i32, void ()*, i32, i32, ...) @llvm.experimental.gc.statepoint.p0f_isVoidf(i64 0, i32 0, void ()* @do_safepoint, i32 0, i32 0, i32 0, i32 0) ["gc-live" (<2 x i8 addrspace(1)*> %obj, <2 x i8 addrspace(1)*> %derived)]
%derived.relocated = call coldcc <2 x i8 addrspace(1)*> @llvm.experimental.gc.relocate.v2p1i8(token %safepoint_token, i32 0, i32 1) ; (%obj, %derived)
ret <2 x i8 addrspace(1)*> %derived.relocated
}
; Originally, this was just a variant of @test2 above, but it ends up
; covering a bunch of interesting missed optimizations. Specifically:
; - We waste a stack slot for a value that a backend transform pass
; CSEd to another spilled one.
; - We don't remove the testb even though it serves no purpose
; - We could in principal reuse the argument memory (%rsi) and do away
; with stack slots entirely.
define <2 x i64 addrspace(1)*> @test3(i1 %cnd, <2 x i64 addrspace(1)*>* %ptr) gc "statepoint-example" {
; CHECK-LABEL: test3:
; CHECK: # %bb.0: # %entry
; CHECK-NEXT: subq $40, %rsp
; CHECK-NEXT: .cfi_def_cfa_offset 48
; CHECK-NEXT: testb $1, %dil
; CHECK-NEXT: movaps (%rsi), %xmm0
; CHECK-NEXT: movaps %xmm0, (%rsp)
; CHECK-NEXT: movaps %xmm0, {{[0-9]+}}(%rsp)
; CHECK-NEXT: callq do_safepoint
; CHECK-NEXT: .Ltmp2:
; CHECK-NEXT: movaps (%rsp), %xmm0
; CHECK-NEXT: addq $40, %rsp
; CHECK-NEXT: .cfi_def_cfa_offset 8
; CHECK-NEXT: retq
entry:
br i1 %cnd, label %taken, label %untaken
taken: ; preds = %entry
%obja = load <2 x i64 addrspace(1)*>, <2 x i64 addrspace(1)*>* %ptr
br label %merge
untaken: ; preds = %entry
%objb = load <2 x i64 addrspace(1)*>, <2 x i64 addrspace(1)*>* %ptr
br label %merge
merge: ; preds = %untaken, %taken
%obj.base = phi <2 x i64 addrspace(1)*> [ %obja, %taken ], [ %objb, %untaken ]
%obj = phi <2 x i64 addrspace(1)*> [ %obja, %taken ], [ %objb, %untaken ]
%safepoint_token = call token (i64, i32, void ()*, i32, i32, ...) @llvm.experimental.gc.statepoint.p0f_isVoidf(i64 0, i32 0, void ()* @do_safepoint, i32 0, i32 0, i32 0, i32 0) ["gc-live" (<2 x i64 addrspace(1)*> %obj, <2 x i64 addrspace(1)*> %obj.base)]
%obj.relocated = call coldcc <2 x i8 addrspace(1)*> @llvm.experimental.gc.relocate.v2p1i8(token %safepoint_token, i32 1, i32 0) ; (%obj.base, %obj)
%obj.relocated.casted = bitcast <2 x i8 addrspace(1)*> %obj.relocated to <2 x i64 addrspace(1)*>
%obj.base.relocated = call coldcc <2 x i8 addrspace(1)*> @llvm.experimental.gc.relocate.v2p1i8(token %safepoint_token, i32 1, i32 1) ; (%obj.base, %obj.base)
%obj.base.relocated.casted = bitcast <2 x i8 addrspace(1)*> %obj.base.relocated to <2 x i64 addrspace(1)*>
ret <2 x i64 addrspace(1)*> %obj.relocated.casted
}
; Can we handle vector constants? At the moment, we don't appear to actually
; get selection dag nodes for these.
define <2 x i8 addrspace(1)*> @test4() gc "statepoint-example" {
; CHECK-LABEL: test4:
; CHECK: # %bb.0: # %entry
; CHECK-NEXT: subq $24, %rsp
; CHECK-NEXT: .cfi_def_cfa_offset 32
; CHECK-NEXT: xorps %xmm0, %xmm0
; CHECK-NEXT: movaps %xmm0, (%rsp)
; CHECK-NEXT: callq do_safepoint
; CHECK-NEXT: .Ltmp3:
; CHECK-NEXT: movaps (%rsp), %xmm0
; CHECK-NEXT: addq $24, %rsp
; CHECK-NEXT: .cfi_def_cfa_offset 8
; CHECK-NEXT: retq
entry:
%safepoint_token = call token (i64, i32, void ()*, i32, i32, ...) @llvm.experimental.gc.statepoint.p0f_isVoidf(i64 0, i32 0, void ()* @do_safepoint, i32 0, i32 0, i32 0, i32 0) ["gc-live" (<2 x i8 addrspace(1)*> zeroinitializer)]
%obj.relocated = call coldcc <2 x i8 addrspace(1)*> @llvm.experimental.gc.relocate.v2p1i8(token %safepoint_token, i32 0, i32 0)
ret <2 x i8 addrspace(1)*> %obj.relocated
}
; Check that we can lower a constant typed as i128 correctly. We don't have
; a representation of larger than 64 bit constant in the StackMap format. At
; the moment, this simply means spilling them, but there's a potential
; optimization for values representable as sext(Con64).
define void @test5() gc "statepoint-example" {
; CHECK-LABEL: test5:
; CHECK: # %bb.0: # %entry
; CHECK-NEXT: subq $40, %rsp
; CHECK-NEXT: .cfi_def_cfa_offset 48
; CHECK-NEXT: xorps %xmm0, %xmm0
; CHECK-NEXT: movups %xmm0, {{[0-9]+}}(%rsp)
; CHECK-NEXT: movq $-1, {{[0-9]+}}(%rsp)
; CHECK-NEXT: movq $-1, {{[0-9]+}}(%rsp)
; CHECK-NEXT: callq do_safepoint
; CHECK-NEXT: .Ltmp4:
; CHECK-NEXT: addq $40, %rsp
; CHECK-NEXT: .cfi_def_cfa_offset 8
; CHECK-NEXT: retq
entry:
%safepoint_token = call token (i64, i32, void ()*, i32, i32, ...) @llvm.experimental.gc.statepoint.p0f_isVoidf(i64 0, i32 0, void ()* @do_safepoint, i32 0, i32 0, i32 0, i32 0) ["deopt" (i128 0, i128 -1)]
ret void
}
; CHECK: __LLVM_StackMaps:
; CHECK: .Ltmp0-test
; Check for the two spill slots
; Stack Maps: Loc 3: Indirect 7+0 [encoding: .byte 3, .byte 0, .short 16, .short 7, .short 0, .int 0]
; Stack Maps: Loc 4: Indirect 7+0 [encoding: .byte 3, .byte 0, .short 16, .short 7, .short 0, .int 0]
; CHECK: .byte 3
; CHECK: .byte 0
; CHECK: .short 16
; CHECK: .short 7
; CHECK: .short 0
; CHECK: .long 0
; CHECK: .byte 3
; CHECK: .byte 0
; CHECK: .short 16
; CHECK: .short 7
; CHECK: .short 0
; CHECK: .long 0
; CHECK: .Ltmp1-test2
; Check for the two spill slots
; Stack Maps: Loc 3: Indirect 7+16 [encoding: .byte 3, .byte 0, .short 16, .short 7, .short 0, .int 16]
; Stack Maps: Loc 4: Indirect 7+0 [encoding: .byte 3, .byte 0, .short 16, .short 7, .short 0, .int 0]
; CHECK: .byte 3
; CHECK: .byte 0
; CHECK: .short 16
; CHECK: .short 7
; CHECK: .short 0
; CHECK: .long 0
; CHECK: .byte 3
; CHECK: .byte 0
; CHECK: .short 16
; CHECK: .short 7
; CHECK: .short 0
; CHECK: .long 16
; CHECK: .Ltmp2-test3
; Check for the four spill slots
; Stack Maps: Loc 3: Indirect 7+16 [encoding: .byte 3, .byte 0, .short 16, .short 7, .short 0, .int 16]
; Stack Maps: Loc 4: Indirect 7+16 [encoding: .byte 3, .byte 0, .short 16, .short 7, .short 0, .int 16]
; Stack Maps: Loc 5: Indirect 7+16 [encoding: .byte 3, .byte 0, .short 16, .short 7, .short 0, .int 16]
; Stack Maps: Loc 6: Indirect 7+0 [encoding: .byte 3, .byte 0, .short 16, .short 7, .short 0, .int 0]
; CHECK: .byte 3
; CHECK: .byte 0
; CHECK: .short 16
; CHECK: .short 7
; CHECK: .short 0
; CHECK: .long 16
; CHECK: .byte 3
; CHECK: .byte 0
; CHECK: .short 16
; CHECK: .short 7
; CHECK: .short 0
; CHECK: .long 16
; CHECK: .byte 3
; CHECK: .byte 0
; CHECK: .short 16
; CHECK: .short 7
; CHECK: .short 0
; CHECK: .long 16
; CHECK: .byte 3
; CHECK: .byte 0
; CHECK: .short 16
; CHECK: .short 7
; CHECK: .short 0
; CHECK: .long 0
declare void @do_safepoint()
declare token @llvm.experimental.gc.statepoint.p0f_isVoidf(i64, i32, void ()*, i32, i32, ...)
declare i8 addrspace(1)* @llvm.experimental.gc.relocate.p1i8(token, i32, i32)
declare <2 x i8 addrspace(1)*> @llvm.experimental.gc.relocate.v2p1i8(token, i32, i32)
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