llvm-6502/test/Transforms/RewriteStatepointsForGC/basics.ll
Sanjoy Das ead2d1fbe0 [Statepoints] Support for "patchable" statepoints.
Summary:
This change adds two new parameters to the statepoint intrinsic, `i64 id`
and `i32 num_patch_bytes`.  `id` gets propagated to the ID field
in the generated StackMap section.  If the `num_patch_bytes` is
non-zero then the statepoint is lowered to `num_patch_bytes` bytes of
nops instead of a call (the spill and reload code remains unchanged).
A non-zero `num_patch_bytes` is useful in situations where a language
runtime requires complete control over how a call is lowered.

This change brings statepoints one step closer to patchpoints.  With
some additional work (that is not part of this patch) it should be
possible to get rid of `TargetOpcode::STATEPOINT` altogether.

PlaceSafepoints generates `statepoint` wrappers with `id` set to
`0xABCDEF00` (the old default value for the ID reported in the stackmap)
and `num_patch_bytes` set to `0`.  This can be made more sophisticated
later.

Reviewers: reames, pgavlin, swaroop.sridhar, AndyAyers

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D9546

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@237214 91177308-0d34-0410-b5e6-96231b3b80d8
2015-05-12 23:52:24 +00:00

88 lines
3.8 KiB
LLVM

; This is a collection of really basic tests for gc.statepoint rewriting.
; RUN: opt %s -rewrite-statepoints-for-gc -S | FileCheck %s
declare void @foo()
; Trivial relocation over a single call
define i8 addrspace(1)* @test1(i8 addrspace(1)* %obj) gc "statepoint-example" {
; CHECK-LABEL: @test1
; CHECK-LABEL: entry:
; CHECK-NEXT: gc.statepoint
; CHECK-NEXT: %obj.relocated = call coldcc i8 addrspace(1)*
entry:
call i32 (i64, i32, void ()*, i32, i32, ...) @llvm.experimental.gc.statepoint.p0f_isVoidf(i64 0, i32 0, void ()* @foo, i32 0, i32 0, i32 0, i32 5, i32 0, i32 -1, i32 0, i32 0, i32 0)
ret i8 addrspace(1)* %obj
}
; Two safepoints in a row (i.e. consistent liveness)
define i8 addrspace(1)* @test2(i8 addrspace(1)* %obj) gc "statepoint-example" {
; CHECK-LABEL: @test2
; CHECK-LABEL: entry:
; CHECK-NEXT: gc.statepoint
; CHECK-NEXT: %obj.relocated = call coldcc i8 addrspace(1)*
; CHECK-NEXT: gc.statepoint
; CHECK-NEXT: %obj.relocated1 = call coldcc i8 addrspace(1)*
entry:
call i32 (i64, i32, void ()*, i32, i32, ...) @llvm.experimental.gc.statepoint.p0f_isVoidf(i64 0, i32 0, void ()* @foo, i32 0, i32 0, i32 0, i32 5, i32 0, i32 -1, i32 0, i32 0, i32 0)
call i32 (i64, i32, void ()*, i32, i32, ...) @llvm.experimental.gc.statepoint.p0f_isVoidf(i64 0, i32 0, void ()* @foo, i32 0, i32 0, i32 0, i32 5, i32 0, i32 -1, i32 0, i32 0, i32 0)
ret i8 addrspace(1)* %obj
}
; A simple derived pointer
define i8 @test3(i8 addrspace(1)* %obj) gc "statepoint-example" {
; CHECK-LABEL: entry:
; CHECK-NEXT: getelementptr
; CHECK-NEXT: gc.statepoint
; CHECK-NEXT: %derived.relocated = call coldcc i8 addrspace(1)*
; CHECK-NEXT: %obj.relocated = call coldcc i8 addrspace(1)*
; CHECK-NEXT: load i8, i8 addrspace(1)* %derived.relocated
; CHECK-NEXT: load i8, i8 addrspace(1)* %obj.relocated
entry:
%derived = getelementptr i8, i8 addrspace(1)* %obj, i64 10
call i32 (i64, i32, void ()*, i32, i32, ...) @llvm.experimental.gc.statepoint.p0f_isVoidf(i64 0, i32 0, void ()* @foo, i32 0, i32 0, i32 0, i32 5, i32 0, i32 -1, i32 0, i32 0, i32 0)
%a = load i8, i8 addrspace(1)* %derived
%b = load i8, i8 addrspace(1)* %obj
%c = sub i8 %a, %b
ret i8 %c
}
; Tests to make sure we visit both the taken and untaken predeccessor
; of merge. This was a bug in the dataflow liveness at one point.
define i8 addrspace(1)* @test4(i1 %cmp, i8 addrspace(1)* %obj) gc "statepoint-example" {
entry:
br i1 %cmp, label %taken, label %untaken
taken:
; CHECK-LABEL: taken:
; CHECK-NEXT: gc.statepoint
; CHECK-NEXT: %obj.relocated = call coldcc i8 addrspace(1)*
call i32 (i64, i32, void ()*, i32, i32, ...) @llvm.experimental.gc.statepoint.p0f_isVoidf(i64 0, i32 0, void ()* @foo, i32 0, i32 0, i32 0, i32 5, i32 0, i32 -1, i32 0, i32 0, i32 0)
br label %merge
untaken:
; CHECK-LABEL: untaken:
; CHECK-NEXT: gc.statepoint
; CHECK-NEXT: %obj.relocated1 = call coldcc i8 addrspace(1)*
call i32 (i64, i32, void ()*, i32, i32, ...) @llvm.experimental.gc.statepoint.p0f_isVoidf(i64 0, i32 0, void ()* @foo, i32 0, i32 0, i32 0, i32 5, i32 0, i32 -1, i32 0, i32 0, i32 0)
br label %merge
merge:
; CHECK-LABEL: merge:
; CHECK-NEXT: %.0 = phi i8 addrspace(1)* [ %obj.relocated, %taken ], [ %obj.relocated1, %untaken ]
; CHECK-NEXT: ret i8 addrspace(1)* %.0
ret i8 addrspace(1)* %obj
}
; When run over a function which doesn't opt in, should do nothing!
define i8 addrspace(1)* @test5(i8 addrspace(1)* %obj) gc "ocaml" {
; CHECK-LABEL: @test5
; CHECK-LABEL: entry:
; CHECK-NEXT: gc.statepoint
; CHECK-NOT: %obj.relocated = call coldcc i8 addrspace(1)*
entry:
call i32 (i64, i32, void ()*, i32, i32, ...) @llvm.experimental.gc.statepoint.p0f_isVoidf(i64 0, i32 0, void ()* @foo, i32 0, i32 0, i32 0, i32 5, i32 0, i32 -1, i32 0, i32 0, i32 0)
ret i8 addrspace(1)* %obj
}
declare i32 @llvm.experimental.gc.statepoint.p0f_isVoidf(i64, i32, void ()*, i32, i32, ...)