llvm/test/Transforms/RewriteStatepointsForGC/constants.ll

; RUN: opt -S -passes=rewrite-statepoints-for-gc < %s | FileCheck %s

target datalayout = "e-ni:1:6"

; constants don't get relocated.
@G = addrspace(1) global i8 5

declare void @foo()

define i8 @test() gc "statepoint-example" {
; CHECK-LABEL: @test
; CHECK: gc.statepoint
; CHECK-NEXT: load i8, ptr addrspace(1) inttoptr (i64 15 to ptr addrspace(1))
; Mostly just here to show reasonable code test can come from.
entry:
  call void @foo() [ "deopt"() ]
  %res = load i8, ptr addrspace(1) inttoptr (i64 15 to ptr addrspace(1))
  ret i8 %res
}

define i8 @test2(ptr addrspace(1) %p) gc "statepoint-example" {
; CHECK-LABEL: @test2
; CHECK: gc.statepoint
; CHECK-NEXT: gc.relocate
; CHECK-NEXT: icmp
; Globals don't move and thus don't get relocated
entry:
  call void @foo() [ "deopt"() ]
  %cmp = icmp eq ptr addrspace(1) %p, null
  br i1 %cmp, label %taken, label %not_taken

taken:                                            ; preds = %not_taken, %entry
  ret i8 0

not_taken:                                        ; preds = %entry
  %cmp2 = icmp ne ptr addrspace(1) %p, null
  br i1 %cmp2, label %taken, label %dead

dead:                                             ; preds = %not_taken
  %addr = getelementptr i8, ptr addrspace(1) %p, i32 15
  %res = load i8, ptr addrspace(1) %addr
  ret i8 %res
}

define i8 @test3(i1 %always_true) gc "statepoint-example" {
; CHECK-LABEL: @test3
; CHECK: gc.statepoint
; CHECK-NEXT: load i8, ptr addrspace(1) @G
entry:
  call void @foo() [ "deopt"() ]
  %res = load i8, ptr addrspace(1) @G, align 1
  ret i8 %res
}

; Even for source languages without constant references, we can
; see constants can show up along paths where the value is dead.
; This is particular relevant when computing bases of PHIs.
define ptr addrspace(1) @test4(ptr addrspace(1) %p) gc "statepoint-example" {
; CHECK-LABEL: @test4
entry:
  %is_null = icmp eq ptr addrspace(1) %p, null
  br i1 %is_null, label %split, label %join

split:
  call void @foo()
  %arg_value_addr.i = getelementptr inbounds i8, ptr addrspace(1) %p, i64 8
  br label %join

join:
; CHECK-LABEL: join
; CHECK: %addr2.base =
  %addr2 = phi ptr addrspace(1) [ %arg_value_addr.i, %split ], [ inttoptr (i64 8 to ptr addrspace(1)), %entry ]
  ;; NOTE: This particular example can be jump-threaded, but in general,
  ;; we can't, and have to deal with the resulting IR.
  br i1 %is_null, label %early-exit, label %use

early-exit:
  ret ptr addrspace(1) null

use:
; CHECK-LABEL: use:
; CHECK: gc.statepoint
; CHECK: gc.relocate
  call void @foo()
  %res = load ptr addrspace(1), ptr addrspace(1) %addr2, align 1
  ret ptr addrspace(1) %res
}

; Globals don't move and thus don't get relocated
define ptr addrspace(1) @test5(i1 %always_true) gc "statepoint-example" {
; CHECK-LABEL: @test5
; CHECK: gc.statepoint
; CHECK-NEXT: %res = extractelement <2 x ptr addrspace(1)> <ptr addrspace(1) @G, ptr addrspace(1) @G>, i32 0
entry:
  call void @foo()
  %res = extractelement <2 x ptr addrspace(1)> <ptr addrspace(1) @G, ptr addrspace(1) @G>, i32 0
  ret ptr addrspace(1) %res
}

define ptr addrspace(1) @test6(i64 %arg) gc "statepoint-example" {
entry:
  ; Don't fail any assertions and don't record null as a live value
  ; CHECK-LABEL: test6
  ; CHECK: gc.statepoint
  ; CHECK-NOT: call {{.*}}gc.relocate
  %load_addr = getelementptr i8, ptr addrspace(1) null, i64 %arg
  call void @foo() [ "deopt"() ]
  ret ptr addrspace(1) %load_addr
}

define ptr addrspace(1) @test7(i64 %arg) gc "statepoint-example" {
entry:
  ; Same as test7 but use regular constant instead of a null
  ; CHECK-LABEL: test7
  ; CHECK: gc.statepoint
  ; CHECK-NOT: call {{.*}}gc.relocate
  %load_addr = getelementptr i8, ptr addrspace(1) inttoptr (i64 15 to ptr addrspace(1)), i64 %arg
  call void @foo() [ "deopt"() ]
  ret ptr addrspace(1) %load_addr
}

define i8 @test8(ptr addrspace(1) %p) gc "statepoint-example" {
; Checks that base( phi(gep null, oop) ) = phi(null, base(oop)) and that we
; correctly relocate this value
; CHECK-LABEL: @test8
entry:
  %is_null = icmp eq ptr addrspace(1) %p, null
  br i1 %is_null, label %null.crit-edge, label %not-null

not-null:
  %load_addr = getelementptr inbounds i8, ptr addrspace(1) %p, i64 8
  br label %join

null.crit-edge:
  %load_addr.const = getelementptr inbounds i8, ptr addrspace(1) null, i64 8
  br label %join

join:
  %addr = phi ptr addrspace(1) [ %load_addr, %not-null ], [%load_addr.const, %null.crit-edge]
  ; CHECK: %addr.base = phi ptr addrspace(1)
  ; CHECK-DAG: [ %p, %not-null ]
  ; CHECK-DAG: [ null, %null.crit-edge ]
  ; CHECK: gc.statepoint
  call void @foo() [ "deopt"() ]
  ; CHECK-DAG: call {{.*}}gc.relocate{{.*}}(%addr.base, %addr.base)
  ; CHECK-DAG: call {{.*}}gc.relocate{{.*}}(%addr.base, %addr)
  br i1 %is_null, label %early-exit, label %use

early-exit:
  ret i8 0

use:
  %res = load i8, ptr addrspace(1) %addr, align 1
  ret i8 %res
}

define i8 @test9(ptr addrspace(1) %p) gc "statepoint-example" {
; Checks that base( phi(inttoptr, oop) ) = phi(null, base(oop)) and that we
; correctly relocate this value
; CHECK-LABEL: @test9
entry:
  %is_null = icmp eq ptr addrspace(1) %p, null
  br i1 %is_null, label %null.crit-edge, label %not-null

not-null:
  %load_addr = getelementptr inbounds i8, ptr addrspace(1) %p, i64 8
  br label %join

null.crit-edge:
  br label %join

join:
  %addr = phi ptr addrspace(1) [ %load_addr, %not-null ], [inttoptr (i64 8 to ptr addrspace(1)), %null.crit-edge]
  ; CHECK: %addr.base = phi ptr addrspace(1)
  ; CHECK-DAG: [ %p, %not-null ]
  ; CHECK-DAG: [ null, %null.crit-edge ]
  ; CHECK: gc.statepoint
  call void @foo() [ "deopt"() ]
  ; CHECK-DAG: call {{.*}}gc.relocate{{.*}}(%addr.base, %addr.base)
  ; CHECK-DAG: call {{.*}}gc.relocate{{.*}}(%addr.base, %addr)
  br i1 %is_null, label %early-exit, label %use

early-exit:
  ret i8 0

use:
  %res = load i8, ptr addrspace(1) %addr, align 1
  ret i8 %res
}

define i8 @test10(ptr addrspace(1) %p) gc "statepoint-example" {
; Checks that base( phi(const gep, oop) ) = phi(null, base(oop)) and that we
; correctly relocate this value
; CHECK-LABEL: @test10
entry:
  %is_null = icmp eq ptr addrspace(1) %p, null
  br i1 %is_null, label %null.crit-edge, label %not-null

not-null:
  %load_addr = getelementptr inbounds i8, ptr addrspace(1) %p, i64 8
  br label %join

null.crit-edge:
  br label %join

join:
  %addr = phi ptr addrspace(1) [ %load_addr, %not-null ], [getelementptr (i8, ptr addrspace(1) null, i64 8), %null.crit-edge]
  ; CHECK: %addr.base = phi ptr addrspace(1)
  ; CHECK-DAG: [ %p, %not-null ]
  ; CHECK-DAG: [ null, %null.crit-edge ]
  ; CHECK: gc.statepoint
  call void @foo() [ "deopt"() ]
  ; CHECK-DAG: call {{.*}}gc.relocate{{.*}}(%addr.base, %addr.base)
  ; CHECK-DAG: call {{.*}}gc.relocate{{.*}}(%addr.base, %addr)
  br i1 %is_null, label %early-exit, label %use

early-exit:
  ret i8 0

use:
  %res = load i8, ptr addrspace(1) %addr, align 1
  ret i8 %res
}

define ptr addrspace(1) @test11(i1 %c) gc "statepoint-example" {
; CHECK-LABEL: @test11
; Checks that base( select(const1, const2) ) == null and that we don't record
; such value in the oop map
entry:
  %val = select i1 %c, ptr addrspace(1) inttoptr (i64 8 to ptr addrspace(1)), ptr addrspace(1) inttoptr (i64 15 to ptr addrspace(1))
  ; CHECK: gc.statepoint
  ; CHECK-NOT: call {{.*}}gc.relocate
  call void @foo() [ "deopt"() ]
  ret ptr addrspace(1) %val
}


define <2 x ptr addrspace(1)> @test12(i1 %c) gc "statepoint-example" {
; CHECK-LABEL: @test12
; Same as test11 but with vectors
entry:
  %val = select i1 %c, <2 x ptr addrspace(1)> <ptr addrspace(1) inttoptr (i64 5 to ptr addrspace(1)),
                                                ptr addrspace(1) inttoptr (i64 15 to ptr addrspace(1))>,
                       <2 x ptr addrspace(1)> <ptr addrspace(1) inttoptr (i64 30 to ptr addrspace(1)),
                                                ptr addrspace(1) inttoptr (i64 60 to ptr addrspace(1))>
  ; CHECK: gc.statepoint
  ; CHECK-NOT: call {{.*}}gc.relocate
  call void @foo() [ "deopt"() ]
  ret <2 x ptr addrspace(1)> %val
}

define <2 x ptr addrspace(1)> @test13(i1 %c, <2 x ptr addrspace(1)> %ptr) gc "statepoint-example" {
; CHECK-LABEL: @test13
; Similar to test8, test9 and test10 but with vectors
entry:
  %val = select i1 %c, <2 x ptr addrspace(1)> %ptr,
                       <2 x ptr addrspace(1)> <ptr addrspace(1) inttoptr (i64 30 to ptr addrspace(1)), ptr addrspace(1) inttoptr (i64 60 to ptr addrspace(1))>
  ; CHECK: %val.base = select i1 %c, <2 x ptr addrspace(1)> %ptr, <2 x ptr addrspace(1)> zeroinitializer, !is_base_value !0
  ; CHECK: gc.statepoint
  call void @foo() [ "deopt"() ]
  ; CHECK-DAG: call {{.*}}gc.relocate{{.*}}(%val.base, %val.base)
  ; CHECK-DAG: call {{.*}}gc.relocate{{.*}}(%val.base, %val)
  ret <2 x ptr addrspace(1)> %val
}

define ptr addrspace(1) @test14() gc "statepoint-example" {
; CHECK-LABEL: @test14
; FIXME: this is a extract element of constant vector and as such should not be relocated, but our current code relocates it since the extractelement will conservatively be marked as conflict during the BDV insertion algorithm. In many cases the extra instruction will be identical to the one already present and will be removed by later phases. 
entry:
  %val = extractelement <2 x ptr addrspace(1)> <ptr addrspace(1) inttoptr (i64 5 to ptr addrspace(1)),
                                                ptr addrspace(1) inttoptr (i64 15 to ptr addrspace(1))>, i32 0
  ; CHECK: gc.statepoint
  call void @foo() [ "deopt"() ]
  ; CHECK-DAG: call {{.*}}gc.relocate{{.*}}(%val.base, %val.base)
  ; CHECK-DAG: call {{.*}}gc.relocate{{.*}}(%val.base, %val)
  ret ptr addrspace(1) %val
}