[RewriteStatepointsForGC] Fix a bug on creating gc_relocate for pointer to vector of pointers

Summary:
In RewriteStatepointsForGC pass, we create a gc_relocate intrinsic for
each relocated pointer, and the gc_relocate has the same type with the
pointer. During the creation of gc_relocate intrinsic, llvm requires to
mangle its type. However, llvm does not support mangling of all possible
types. RewriteStatepointsForGC will hit an assertion failure when it
tries to create a gc_relocate for pointer to vector of pointers because
mangling for vector of pointers is not supported.

This patch changes the way RewriteStatepointsForGC pass creates
gc_relocate. For each relocated pointer, we erase the type of pointers
and create an unified gc_relocate of type i8 addrspace(1)*. Then a
bitcast is inserted to convert the gc_relocate to the correct type. In
this way, gc_relocate does not need to deal with different types of
pointers and the unsupported type mangling is no longer a problem. This
change would also ease further merge when LLVM erases types of pointers
and introduces an unified pointer type.

Some minor changes are also introduced to gc_relocate related part in
InstCombineCalls, CodeGenPrepare, and Verifier accordingly.

Patch by Chen Li!

Reviewers: reames, AndyAyers, sanjoy

Reviewed By: sanjoy

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D9592

llvm-svn: 237009
diff --git a/llvm/test/Transforms/RewriteStatepointsForGC/base-pointers-11.ll b/llvm/test/Transforms/RewriteStatepointsForGC/base-pointers-11.ll
index 2fc9d42..11e252f 100644
--- a/llvm/test/Transforms/RewriteStatepointsForGC/base-pointers-11.ll
+++ b/llvm/test/Transforms/RewriteStatepointsForGC/base-pointers-11.ll
@@ -12,11 +12,11 @@
 loop:                                             ; preds = %loop, %entry
 ; CHECK-LABEL: loop:
 ; CHECK: phi i64 addrspace(1)*
-; CHECK-DAG:  [ %base_obj.relocated, %loop ] 
+; CHECK-DAG:  [ %base_obj.relocated.casted, %loop ] 
 ; CHECK-DAG:  [ %base_obj, %entry ]
 ; CHECK:  %current = phi i64 addrspace(1)* 
 ; CHECK-DAG:  [ %obj, %entry ]
-; CHECK-DAG:  [ %next.relocated, %loop ]
+; CHECK-DAG:  [ %next.relocated.casted, %loop ]
   %current = phi i64 addrspace(1)* [ %obj, %entry ], [ %next, %loop ]
   %next = getelementptr i64, i64 addrspace(1)* %current, i32 1
   %safepoint_token = call i32 (void ()*, i32, i32, ...) @llvm.experimental.gc.statepoint.p0f_isVoidf(void ()* @do_safepoint, i32 0, i32 0, i32 0, i32 5, i32 0, i32 -1, i32 0, i32 0, i32 0)
diff --git a/llvm/test/Transforms/RewriteStatepointsForGC/base-pointers.ll b/llvm/test/Transforms/RewriteStatepointsForGC/base-pointers.ll
index e88f6df..2652d36 100644
--- a/llvm/test/Transforms/RewriteStatepointsForGC/base-pointers.ll
+++ b/llvm/test/Transforms/RewriteStatepointsForGC/base-pointers.ll
@@ -13,7 +13,7 @@
 
 loop:
 ; CHECK: phi i64 addrspace(1)* 
-; CHECK-DAG: [ %obj.relocated, %loop ]
+; CHECK-DAG: [ %obj.relocated.casted, %loop ]
 ; CHECK-DAG: [ %obj, %entry ]
   call void @use_obj(i64 addrspace(1)* %obj)
   %safepoint_token = call i32 (void ()*, i32, i32, ...) @llvm.experimental.gc.statepoint.p0f_isVoidf(void ()* @do_safepoint, i32 0, i32 0, i32 0, i32 5, i32 0, i32 -1, i32 0, i32 0, i32 0)
@@ -78,7 +78,7 @@
 ; CHECK-DAG: [ %base_obj, %entry ]
 ; Given the two selects are equivelent, so are their base phis - ideally,
 ; we'd have commoned these, but that's a missed optimization, not correctness.
-; CHECK-DAG: [ [[DISCARD:%base_select.*.relocated]], %loop ]
+; CHECK-DAG: [ [[DISCARD:%base_select.*.relocated.casted]], %loop ]
 ; CHECK-NOT: base_phi2
 ; CHECK: next = select
 ; CHECK: base_select
diff --git a/llvm/test/Transforms/RewriteStatepointsForGC/gc_relocate_creation.ll b/llvm/test/Transforms/RewriteStatepointsForGC/gc_relocate_creation.ll
new file mode 100644
index 0000000..ab57f31
--- /dev/null
+++ b/llvm/test/Transforms/RewriteStatepointsForGC/gc_relocate_creation.ll
@@ -0,0 +1,20 @@
+; RUN: opt %s -rewrite-statepoints-for-gc -S 2>&1 | FileCheck %s
+; This test is to verify gc.relocate can handle pointer to vector of
+; pointers (<2 x i32 addrspace(1)*> addrspace(1)* in this case).
+; The old scheme to create a gc.relocate of <2 x i32 addrspace(1)*> addrspace(1)*
+; type will fail because llvm does not support mangling vector of pointers.
+; The new scheme will create all gc.relocate to i8 addrspace(1)* type and
+; then bitcast to the correct type.
+
+declare void @foo()
+declare void @use(...)
+declare i32 @llvm.experimental.gc.statepoint.p0f_isVoidf(void ()*, i32, i32, ...)
+
+define void @test1(<2 x i32 addrspace(1)*> addrspace(1)* %obj) gc "statepoint-example" {
+entry:
+  %safepoint_token = call i32 (void ()*, i32, i32, ...) @llvm.experimental.gc.statepoint.p0f_isVoidf(void ()* @foo, i32 0, i32 0, i32 0, i32 0)
+; CHECK: %obj.relocated = call coldcc i8 addrspace(1)* @llvm.experimental.gc.relocate.p1i8(i32 %safepoint_token, i32 5, i32 5)
+; CHECK-NEXT:  %obj.relocated.casted = bitcast i8 addrspace(1)* %obj.relocated to <2 x i32 addrspace(1)*> addrspace(1)*
+  call void (...) @use(<2 x i32 addrspace(1)*> addrspace(1)* %obj)
+  ret void
+}
\ No newline at end of file
diff --git a/llvm/test/Transforms/RewriteStatepointsForGC/live-vector.ll b/llvm/test/Transforms/RewriteStatepointsForGC/live-vector.ll
index 4513681..b827133 100644
--- a/llvm/test/Transforms/RewriteStatepointsForGC/live-vector.ll
+++ b/llvm/test/Transforms/RewriteStatepointsForGC/live-vector.ll
@@ -7,7 +7,8 @@
 ; CHECK-LABEL: test
 ; CHECK: gc.statepoint
 ; CHECK-NEXT: gc.relocate
-; CHECK-NEXT: ret i64 addrspace(1)* %obj.relocated
+; CHECK-NEXT: bitcast
+; CHECK-NEXT: ret i64 addrspace(1)* %obj.relocated.casted
 entry:
   %safepoint_token = call i32 (void ()*, i32, i32, ...) @llvm.experimental.gc.statepoint.p0f_isVoidf(void ()* @do_safepoint, i32 0, i32 0, i32 0, i32 0)
   ret i64 addrspace(1)* %obj
@@ -20,10 +21,12 @@
 ; CHECK-NEXT: extractelement
 ; CHECK-NEXT: gc.statepoint
 ; CHECK-NEXT: gc.relocate
+; CHECK-NEXT: bitcast
 ; CHECK-NEXT: gc.relocate
+; CHECK-NEXT: bitcast
 ; CHECK-NEXT: insertelement
 ; CHECK-NEXT: insertelement
-; CHECK-NEXT: ret <2 x i64 addrspace(1)*> %5
+; CHECK-NEXT: ret <2 x i64 addrspace(1)*> %7
 entry:
   %safepoint_token = call i32 (void ()*, i32, i32, ...) @llvm.experimental.gc.statepoint.p0f_isVoidf(void ()* @do_safepoint, i32 0, i32 0, i32 0, i32 0)
   ret <2 x i64 addrspace(1)*> %obj
@@ -37,10 +40,12 @@
 ; CHECK-NEXT: extractelement
 ; CHECK-NEXT: gc.statepoint
 ; CHECK-NEXT: gc.relocate
+; CHECK-NEXT: bitcast
 ; CHECK-NEXT: gc.relocate
+; CHECK-NEXT: bitcast
 ; CHECK-NEXT: insertelement
 ; CHECK-NEXT: insertelement
-; CHECK-NEXT: ret <2 x i64 addrspace(1)*> %5
+; CHECK-NEXT: ret <2 x i64 addrspace(1)*> %7
 entry:
   %obj = load <2 x i64 addrspace(1)*>, <2 x i64 addrspace(1)*>* %ptr
   %safepoint_token = call i32 (void ()*, i32, i32, ...) @llvm.experimental.gc.statepoint.p0f_isVoidf(void ()* @do_safepoint, i32 0, i32 0, i32 0, i32 0)
@@ -63,19 +68,23 @@
 
 ; CHECK-LABEL: normal_return:
 ; CHECK: gc.relocate
+; CHECK-NEXT: bitcast
 ; CHECK-NEXT: gc.relocate
+; CHECK-NEXT: bitcast
 ; CHECK-NEXT: insertelement
 ; CHECK-NEXT: insertelement
-; CHECK-NEXT: ret <2 x i64 addrspace(1)*> %6
+; CHECK-NEXT: ret <2 x i64 addrspace(1)*> %8
 normal_return:                                    ; preds = %entry
   ret <2 x i64 addrspace(1)*> %obj
 
 ; CHECK-LABEL: exceptional_return:
 ; CHECK: gc.relocate
+; CHECK-NEXT: bitcast
 ; CHECK-NEXT: gc.relocate
+; CHECK-NEXT: bitcast
 ; CHECK-NEXT: insertelement
 ; CHECK-NEXT: insertelement
-; CHECK-NEXT: ret <2 x i64 addrspace(1)*> %10
+; CHECK-NEXT: ret <2 x i64 addrspace(1)*> %14
 exceptional_return:                               ; preds = %entry
   %landing_pad4 = landingpad { i8*, i32 } personality i32 ()* @fake_personality_function
           cleanup
diff --git a/llvm/test/Transforms/RewriteStatepointsForGC/liveness-basics.ll b/llvm/test/Transforms/RewriteStatepointsForGC/liveness-basics.ll
index 6da6b7c..a4b427c 100644
--- a/llvm/test/Transforms/RewriteStatepointsForGC/liveness-basics.ll
+++ b/llvm/test/Transforms/RewriteStatepointsForGC/liveness-basics.ll
@@ -13,7 +13,8 @@
 taken:
 ; CHECK-LABEL: taken:
 ; CHECK-NEXT: gc.statepoint
-; CHECK-NEXT: %obj.relocated = call coldcc i64 addrspace(1)*
+; 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)
   br label %merge
@@ -21,14 +22,15 @@
 untaken:
 ; CHECK-LABEL: untaken:
 ; CHECK-NEXT: gc.statepoint
-; CHECK-NEXT: %obj.relocated1 = call coldcc i64 addrspace(1)*
+; 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)
   br label %merge
 
 merge:
 ; CHECK-LABEL: merge:
-; CHECK-NEXT: %.0 = phi i64 addrspace(1)* [ %obj.relocated, %taken ], [ %obj.relocated1, %untaken ]
+; CHECK-NEXT: %.0 = phi i64 addrspace(1)* [ %obj.relocated.casted, %taken ], [ %obj.relocated1.casted, %untaken ]
 ; CHECK-NEXT: ret i64 addrspace(1)* %.0
   ret i64 addrspace(1)* %obj
 }
@@ -48,7 +50,8 @@
 ; CHECK-NEXT:  %obj = load
 ; CHECK-NEXT:  gc.statepoint
 ; CHECK-NEXT:  gc.relocate
-; CHECK-NEXT:  ret i64 addrspace(1)* %obj.relocated
+; CHECK-NEXT: bitcast
+; 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)
@@ -70,7 +73,8 @@
 ; CHECK-NEXT: gc.statepoint
 ; CHECK-NEXT: %obj = load
 ; CHECK-NEXT: gc.statepoint
-; CHECK-NEXT: %obj.relocated = call coldcc i64 addrspace(1)*
+; 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)
   %obj = load i64 addrspace(1)*, i64 addrspace(1)** %loc
@@ -97,13 +101,17 @@
 ; CHECK-LABEL: entry:
 ; CHECK-NEXT:  %derived = getelementptr
 ; CHECK-NEXT:  gc.statepoint
-; CHECK-NEXT:  %derived.relocated = 
+; CHECK-NEXT:  %derived.relocated =
+; CHECK-NEXT:  bitcast 
 ; CHECK-NEXT:  %obj.relocated =
+; CHECK-NEXT:  bitcast
 ; CHECK-NEXT:  gc.statepoint
-; CHECK-NEXT:  %derived.relocated1 = 
+; CHECK-NEXT:  %derived.relocated1 =
+; CHECK-NEXT:  bitcast 
 ; Note: It's legal to relocate obj again, but not strictly needed
 ; CHECK-NEXT:  %obj.relocated2 =
-; CHECK-NEXT:  ret i64 addrspace(1)* %derived.relocated1
+; CHECK-NEXT:  bitcast
+; 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)
@@ -125,7 +133,8 @@
 taken:
 ; CHECK-LABEL: taken:
 ; CHECK-NEXT: gc.statepoint
-; CHECK-NEXT: %obj.relocated = call coldcc i64 addrspace(1)*
+; 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)
   br label %merge
diff --git a/llvm/test/Transforms/RewriteStatepointsForGC/preprocess.ll b/llvm/test/Transforms/RewriteStatepointsForGC/preprocess.ll
index ffdfe5b..39567b1 100644
--- a/llvm/test/Transforms/RewriteStatepointsForGC/preprocess.ll
+++ b/llvm/test/Transforms/RewriteStatepointsForGC/preprocess.ll
@@ -13,8 +13,9 @@
 ; CHECK-LABEL: next:
 ; CHECK-NEXT: gc.statepoint
 ; CHECK-NEXT: gc.relocate
-; CHECK-NEXT: @consume(i64 addrspace(1)* %obj.relocated)
-; CHECK-NEXT: @consume(i64 addrspace(1)* %obj.relocated)
+; CHECK-NEXT: bitcast
+; CHECK-NEXT: @consume(i64 addrspace(1)* %obj.relocated.casted)
+; CHECK-NEXT: @consume(i64 addrspace(1)* %obj.relocated.casted)
   %obj2 = phi i64 addrspace(1)* [ %obj, %entry ]
   call i32 (void ()*, i32, i32, ...) @llvm.experimental.gc.statepoint.p0f_isVoidf(void ()* @foo, i32 0, i32 0, i32 0, i32 0)
   call void (...) @consume(i64 addrspace(1)* %obj2)
diff --git a/llvm/test/Transforms/RewriteStatepointsForGC/relocate_invoke_result.ll b/llvm/test/Transforms/RewriteStatepointsForGC/relocate_invoke_result.ll
index 80579e6..9afd61d 100644
--- a/llvm/test/Transforms/RewriteStatepointsForGC/relocate_invoke_result.ll
+++ b/llvm/test/Transforms/RewriteStatepointsForGC/relocate_invoke_result.ll
@@ -23,7 +23,8 @@
 normal_dest:
 ;; CHECK-LABEL: normal_dest:
 ;; CHECK-NEXT: gc.statepoint
-;; CHECK-NEXT: %obj.relocated = call coldcc i64* addrspace(1)*                                      
+;; CHECK-NEXT: %obj.relocated = call coldcc i8 addrspace(1)*  
+;; CHECK-NEXT: bitcast                                    
   %safepoint_token = call i32 (void ()*, i32, i32, ...) @llvm.experimental.gc.statepoint.p0f_isVoidf(void ()* @gc_call, i32 0, i32 0, i32 0, i32 5, i32 0, i32 -1, i32 0, i32 0, i32 0)
   ret i64* addrspace(1)* %obj
 }
diff --git a/llvm/test/Transforms/RewriteStatepointsForGC/relocation.ll b/llvm/test/Transforms/RewriteStatepointsForGC/relocation.ll
index f604885..b274c64 100644
--- a/llvm/test/Transforms/RewriteStatepointsForGC/relocation.ll
+++ b/llvm/test/Transforms/RewriteStatepointsForGC/relocation.ll
@@ -14,7 +14,7 @@
 
 joint:
 ; CHECK-LABEL: joint:
-; CHECK: %phi1 = phi i64 addrspace(1)* [ %obj.relocated, %entry ], [ %obj3, %joint2 ]
+; CHECK: %phi1 = phi i64 addrspace(1)* [ %obj.relocated.casted, %entry ], [ %obj3, %joint2 ]
   %phi1 = phi i64 addrspace(1)* [ %obj, %entry ], [ %obj3, %joint2 ]
   br i1 %condition, label %use, label %joint2
 
@@ -23,8 +23,8 @@
 
 joint2:
 ; CHECK-LABEL: joint2:
-; CHECK: %phi2 = phi i64 addrspace(1)* [ %obj.relocated, %use ], [ %obj2.relocated, %joint ]
-; CHECK: %obj3 = getelementptr i64, i64 addrspace(1)* %obj2.relocated, i32 1
+; CHECK: %phi2 = phi i64 addrspace(1)* [ %obj.relocated.casted, %use ], [ %obj2.relocated.casted, %joint ]
+; CHECK: %obj3 = getelementptr i64, i64 addrspace(1)* %obj2.relocated.casted, i32 1
   %phi2 = phi i64 addrspace(1)* [ %obj, %use ], [ %obj2, %joint ]
   %obj3 = getelementptr i64, i64 addrspace(1)* %obj2, i32 1
   br label %joint
@@ -45,9 +45,9 @@
 
 loop:
 ; CHECK: loop:
-; CHECK-DAG: [ %obj_init.relocated, %loop.backedge ]
+; CHECK-DAG: [ %obj_init.relocated.casted, %loop.backedge ]
 ; CHECK-DAG: [ %obj_init, %entry ]
-; CHECK-DAG: [ %obj.relocated, %loop.backedge ]
+; CHECK-DAG: [ %obj.relocated.casted, %loop.backedge ]
 ; CHECK-DAG: [ %obj, %entry ]
   %index = phi i32 [ 0, %entry ], [ %index.inc, %loop.backedge ]
 ; CHECK-NOT: %location = getelementptr i64, i64 addrspace(1)* %obj, i32 %index
@@ -108,6 +108,7 @@
 ; CHECK-LABEL: @test3
 ; CHECK: gc.statepoint
 ; CHECK-NEXT: gc.relocate
+; CHECK-NEXT: bitcast
 ; CHECK-NEXT: gc.statepoint
   %safepoint_token = call i32 (void (i64)*, i32, i32, ...) @llvm.experimental.gc.statepoint.p0f_isVoidi64f(void (i64)* undef, i32 1, i32 0, i64 undef, i32 0, i32 5, i32 0, i32 -1, i32 0, i32 0, i32 0)
   %safepoint_token1 = call i32 (i32 (i64 addrspace(1)*)*, i32, i32, ...) @llvm.experimental.gc.statepoint.p0f_i32p1i64f(i32 (i64 addrspace(1)*)* undef, i32 1, i32 0, i64 addrspace(1)* %obj, i32 0, i32 5, i32 0, i32 -1, i32 0, i32 0, i32 0)
@@ -262,10 +263,10 @@
 
 join:
 ; CHECK-LABEL: join:
-; CHECK: phi i64 addrspace(1)* [ %obj.relocated, %callbb ], [ %obj, %entry ]
+; CHECK: phi i64 addrspace(1)* [ %obj.relocated.casted, %callbb ], [ %obj, %entry ]
 ; CHECK: phi i64 addrspace(1)* 
 ; CHECK-DAG: [ %obj, %entry ]
-; CHECK-DAG: [ %obj2.relocated, %callbb ]
+; CHECK-DAG: [ %obj2.relocated.casted, %callbb ]
   ; This is a phi outside the dominator region of the new defs inserted by
   ; the safepoint, BUT we can't stop the search here or we miss the second
   ; phi below.