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	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
		
			
				
	
	
		
			21 lines
		
	
	
		
			896 B
		
	
	
	
		
			LLVM
		
	
	
	
	
	
			
		
		
	
	
			21 lines
		
	
	
		
			896 B
		
	
	
	
		
			LLVM
		
	
	
	
	
	
| ; RUN: opt %s -rewrite-statepoints-for-gc -spp-print-base-pointers -S  2>&1 | FileCheck %s
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| 
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| ; CHECK: derived %next base %base_obj
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| 
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| declare i1 @runtime_value()
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| 
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| define void @maybe_GEP(i64 addrspace(1)* %base_obj) gc "statepoint-example" {
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| entry:
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|   br label %loop
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| 
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| loop:
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|   %current = phi i64 addrspace(1)* [ %base_obj, %entry ], [ %next, %loop ]
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|   %condition = call i1 @runtime_value()
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|   %maybe_next = getelementptr i64, i64 addrspace(1)* %current, i32 1
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|   %next = select i1 %condition, i64 addrspace(1)* %maybe_next, i64 addrspace(1)* %current
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|   %safepoint_token = call i32 (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 5, i32 0, i32 -1, i32 0, i32 0, i32 0)
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|   br label %loop
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| }
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| 
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| declare void @do_safepoint()
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| declare i32 @llvm.experimental.gc.statepoint.p0f_isVoidf(i64, i32, void ()*, i32, i32, ...) |