1 files changed, 60 insertions, 0 deletions
diff --git a/test/CodeGen/X86/statepoint-stack-usage.ll b/test/CodeGen/X86/statepoint-stack-usage.ll
new file mode 100644
index 0000000..3ecef33
--- /dev/null
+++ b/test/CodeGen/X86/statepoint-stack-usage.ll
@@ -0,0 +1,60 @@
+; 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 {
+; CHECK-LABEL: back_to_back_calls
+; The exact stores don't matter, but there need to be three stack slots created
+; CHECK: movq	%rdx, 16(%rsp)
+; CHECK: movq	%rdi, 8(%rsp)
+; CHECK: movq	%rsi, (%rsp)
+  %safepoint_token = tail call i32 (void ()*, i32, i32, ...)* @llvm.experimental.gc.statepoint.p0f_isVoidf(void ()* undef, 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 9, i32 9)
+  %b1 = tail call coldcc i32 addrspace(1)* @llvm.experimental.gc.relocate.p1i32(i32 %safepoint_token, i32 9, i32 10)
+  %c1 = tail call coldcc i32 addrspace(1)* @llvm.experimental.gc.relocate.p1i32(i32 %safepoint_token, i32 9, i32 11)
+; CHECK: callq
+; This is the key check.  There should NOT be any memory moves here
+; CHECK-NOT: movq
+  %safepoint_token2 = tail call i32 (void ()*, i32, i32, ...)* @llvm.experimental.gc.statepoint.p0f_isVoidf(void ()* undef, 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 9, i32 11)
+  %b2 = tail call coldcc i32 addrspace(1)* @llvm.experimental.gc.relocate.p1i32(i32 %safepoint_token2, i32 9, i32 10)
+  %c2 = tail call coldcc i32 addrspace(1)* @llvm.experimental.gc.relocate.p1i32(i32 %safepoint_token2, i32 9, i32 9)
+; 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 {
+; CHECK-LABEL: reserve_first
+; The exact stores don't matter, but there need to be three stack slots created
+; CHECK: movq	%rdx, 16(%rsp)
+; CHECK: movq	%rdi, 8(%rsp)
+; CHECK: movq	%rsi, (%rsp)
+  %safepoint_token = tail call i32 (void ()*, i32, i32, ...)* @llvm.experimental.gc.statepoint.p0f_isVoidf(void ()* undef, 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 9, i32 9)
+  %b1 = tail call coldcc i32 addrspace(1)* @llvm.experimental.gc.relocate.p1i32(i32 %safepoint_token, i32 9, i32 10)
+  %c1 = tail call coldcc i32 addrspace(1)* @llvm.experimental.gc.relocate.p1i32(i32 %safepoint_token, i32 9, i32 11)
+; CHECK: callq
+; This is the key check.  There should NOT be any memory moves here
+; CHECK-NOT: movq
+  %safepoint_token2 = tail call i32 (void ()*, i32, i32, ...)* @llvm.experimental.gc.statepoint.p0f_isVoidf(void ()* undef, 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 9, i32 11)
+  %b2 = tail call coldcc i32 addrspace(1)* @llvm.experimental.gc.relocate.p1i32(i32 %safepoint_token2, i32 9, i32 10)
+  %c2 = tail call coldcc i32 addrspace(1)* @llvm.experimental.gc.relocate.p1i32(i32 %safepoint_token2, i32 9, i32 9)
+; 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(void ()*, i32, i32, ...)
+
+attributes #1 = { uwtable }