[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

llvm-svn: 237214

1 files changed, 11 insertions, 12 deletions

diff --git a/llvm/test/Transforms/RewriteStatepointsForGC/liveness-basics.ll b/llvm/test/Transforms/RewriteStatepointsForGC/liveness-basics.ll
index a4b427c7f79..4078c3c7d4d 100644
--- a/llvm/test/Transforms/RewriteStatepointsForGC/liveness-basics.ll
+++ b/llvm/test/Transforms/RewriteStatepointsForGC/liveness-basics.ll
@@ -16,7 +16,7 @@ taken:
 ; CHECK-NEXT: %obj.relocated = call coldcc i8 addrspace(1)*
 ; CHECK-NEXT: bitcast
 ; CHECK-NEXT: br label %merge
-  call i32 (void ()*, i32, i32, ...) @llvm.experimental.gc.statepoint.p0f_isVoidf(void ()* @foo, i32 0, 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 0)
   br label %merge
 
 untaken:
@@ -25,7 +25,7 @@ untaken:
 ; CHECK-NEXT: %obj.relocated1 = call coldcc i8 addrspace(1)*
 ; CHECK-NEXT: bitcast
 ; CHECK-NEXT: br label %merge
-  call i32 (void ()*, i32, i32, ...) @llvm.experimental.gc.statepoint.p0f_isVoidf(void ()* @foo, i32 0, 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 0)
   br label %merge
 
 merge:
@@ -42,7 +42,7 @@ entry:
 ; CHECK-LABEL: entry:
 ; CHECK-NEXT:  gc.statepoint
 ; CHECK-NEXT:  br
-  call i32 (void ()*, i32, i32, ...) @llvm.experimental.gc.statepoint.p0f_isVoidf(void ()* @foo, i32 0, 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 0)
   br i1 %cmp, label %taken, label %untaken
 
 taken:
@@ -54,7 +54,7 @@ taken:
 ; CHECK-NEXT:  ret i64 addrspace(1)* %obj.relocated.casted
 
   %obj = load i64 addrspace(1)*, i64 addrspace(1)** %loc
-  call i32 (void ()*, i32, i32, ...) @llvm.experimental.gc.statepoint.p0f_isVoidf(void ()* @foo, i32 0, 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 0)
   ret i64 addrspace(1)* %obj
 
 untaken:
@@ -76,16 +76,16 @@ taken:
 ; CHECK-NEXT: %obj.relocated = call coldcc i8 addrspace(1)*
 ; CHECK-NEXT: bitcast
 ; CHECK-NEXT: br label %merge
-  call i32 (void ()*, i32, i32, ...) @llvm.experimental.gc.statepoint.p0f_isVoidf(void ()* @foo, i32 0, 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 0)
   %obj = load i64 addrspace(1)*, i64 addrspace(1)** %loc
-  call i32 (void ()*, i32, i32, ...) @llvm.experimental.gc.statepoint.p0f_isVoidf(void ()* @foo, i32 0, 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 0)
   br label %merge
 
 untaken:
 ; CHECK-LABEL: taken:
 ; CHECK-NEXT: gc.statepoint
 ; CHECK-NEXT: br label %merge
-  call i32 (void ()*, i32, i32, ...) @llvm.experimental.gc.statepoint.p0f_isVoidf(void ()* @foo, i32 0, 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 0)
   br label %merge
 
 merge:
@@ -114,9 +114,9 @@ entry:
 ; CHECK-NEXT:  ret i64 addrspace(1)* %derived.relocated1.casted
 ; 
   %derived = getelementptr i64, i64 addrspace(1)* %obj, i64 8
-  call i32 (void ()*, i32, i32, ...) @llvm.experimental.gc.statepoint.p0f_isVoidf(void ()* @foo, i32 0, 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 0)
 
-  call i32 (void ()*, i32, i32, ...) @llvm.experimental.gc.statepoint.p0f_isVoidf(void ()* @foo, i32 0, 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 0)
   ret i64 addrspace(1)* %derived
 }
 
@@ -136,7 +136,7 @@ taken:
 ; CHECK-NEXT: %obj.relocated = call coldcc i8 addrspace(1)*
 ; CHECK-NEXT: bitcast
 ; CHECK-NEXT: br label %merge
-  call i32 (void ()*, i32, i32, ...) @llvm.experimental.gc.statepoint.p0f_isVoidf(void ()* @foo, i32 0, 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 0)
   br label %merge
 
 untaken:
@@ -163,5 +163,4 @@ final:
 
 declare void @foo()
 
-declare i32 @llvm.experimental.gc.statepoint.p0f_isVoidf(void ()*, i32, i32, ...)
-
+declare i32 @llvm.experimental.gc.statepoint.p0f_isVoidf(i64, i32, void ()*, i32, i32, ...)