llvm-6502/test/CodeGen/X86/statepoint-stack-usage.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

60 lines
4.2 KiB
LLVM

; RUN: llc < %s | FileCheck %s
target datalayout = "e-i64:64-f80:128-n8:16:32:64-S128"
target triple = "x86_64-pc-linux-gnu"
; This test is checking to make sure that we reuse the same stack slots
; for GC values spilled over two different call sites. Since the order
; of GC arguments differ, niave lowering code would insert loads and
; stores to rearrange items on the stack. We need to make sure (for
; performance) that this doesn't happen.
define i32 @back_to_back_calls(i32 addrspace(1)* %a, i32 addrspace(1)* %b, i32 addrspace(1)* %c) #1 gc "statepoint-example" {
; CHECK-LABEL: back_to_back_calls
; The exact stores don't matter, but there need to be three stack slots created
; CHECK: movq %rdi, 16(%rsp)
; CHECK: movq %rdx, 8(%rsp)
; CHECK: movq %rsi, (%rsp)
%safepoint_token = tail call i32 (i64, i32, void ()*, i32, i32, ...) @llvm.experimental.gc.statepoint.p0f_isVoidf(i64 0, i32 0, void ()* undef, i32 0, i32 0, i32 0, i32 5, i32 0, i32 -1, i32 0, i32 0, i32 0, i32 addrspace(1)* %a, i32 addrspace(1)* %b, i32 addrspace(1)* %c)
%a1 = tail call coldcc i32 addrspace(1)* @llvm.experimental.gc.relocate.p1i32(i32 %safepoint_token, i32 12, i32 12)
%b1 = tail call coldcc i32 addrspace(1)* @llvm.experimental.gc.relocate.p1i32(i32 %safepoint_token, i32 12, i32 13)
%c1 = tail call coldcc i32 addrspace(1)* @llvm.experimental.gc.relocate.p1i32(i32 %safepoint_token, i32 12, i32 14)
; CHECK: callq
; This is the key check. There should NOT be any memory moves here
; CHECK-NOT: movq
%safepoint_token2 = tail call i32 (i64, i32, void ()*, i32, i32, ...) @llvm.experimental.gc.statepoint.p0f_isVoidf(i64 0, i32 0, void ()* undef, i32 0, i32 0, i32 0, i32 5, i32 0, i32 -1, i32 0, i32 0, i32 0, i32 addrspace(1)* %c1, i32 addrspace(1)* %b1, i32 addrspace(1)* %a1)
%a2 = tail call coldcc i32 addrspace(1)* @llvm.experimental.gc.relocate.p1i32(i32 %safepoint_token2, i32 12, i32 14)
%b2 = tail call coldcc i32 addrspace(1)* @llvm.experimental.gc.relocate.p1i32(i32 %safepoint_token2, i32 12, i32 13)
%c2 = tail call coldcc i32 addrspace(1)* @llvm.experimental.gc.relocate.p1i32(i32 %safepoint_token2, i32 12, i32 12)
; CHECK: callq
ret i32 1
}
; This test simply checks that minor changes in vm state don't prevent slots
; being reused for gc values.
define i32 @reserve_first(i32 addrspace(1)* %a, i32 addrspace(1)* %b, i32 addrspace(1)* %c) #1 gc "statepoint-example" {
; CHECK-LABEL: reserve_first
; The exact stores don't matter, but there need to be three stack slots created
; CHECK: movq %rdi, 16(%rsp)
; CHECK: movq %rdx, 8(%rsp)
; CHECK: movq %rsi, (%rsp)
%safepoint_token = tail call i32 (i64, i32, void ()*, i32, i32, ...) @llvm.experimental.gc.statepoint.p0f_isVoidf(i64 0, i32 0, void ()* undef, i32 0, i32 0, i32 0, i32 5, i32 0, i32 -1, i32 0, i32 0, i32 0, i32 addrspace(1)* %a, i32 addrspace(1)* %b, i32 addrspace(1)* %c)
%a1 = tail call coldcc i32 addrspace(1)* @llvm.experimental.gc.relocate.p1i32(i32 %safepoint_token, i32 12, i32 12)
%b1 = tail call coldcc i32 addrspace(1)* @llvm.experimental.gc.relocate.p1i32(i32 %safepoint_token, i32 12, i32 13)
%c1 = tail call coldcc i32 addrspace(1)* @llvm.experimental.gc.relocate.p1i32(i32 %safepoint_token, i32 12, i32 14)
; CHECK: callq
; This is the key check. There should NOT be any memory moves here
; CHECK-NOT: movq
%safepoint_token2 = tail call i32 (i64, i32, void ()*, i32, i32, ...) @llvm.experimental.gc.statepoint.p0f_isVoidf(i64 0, i32 0, void ()* undef, i32 0, i32 0, i32 0, i32 5, i32 addrspace(1)* %a1, i32 0, i32 addrspace(1)* %c1, i32 0, i32 0, i32 addrspace(1)* %c1, i32 addrspace(1)* %b1, i32 addrspace(1)* %a1)
%a2 = tail call coldcc i32 addrspace(1)* @llvm.experimental.gc.relocate.p1i32(i32 %safepoint_token2, i32 12, i32 14)
%b2 = tail call coldcc i32 addrspace(1)* @llvm.experimental.gc.relocate.p1i32(i32 %safepoint_token2, i32 12, i32 13)
%c2 = tail call coldcc i32 addrspace(1)* @llvm.experimental.gc.relocate.p1i32(i32 %safepoint_token2, i32 12, i32 12)
; CHECK: callq
ret i32 1
}
; Function Attrs: nounwind
declare i32 addrspace(1)* @llvm.experimental.gc.relocate.p1i32(i32, i32, i32) #3
declare i32 @llvm.experimental.gc.statepoint.p0f_isVoidf(i64, i32, void ()*, i32, i32, ...)
attributes #1 = { uwtable }