break;
}
+ case Intrinsic::experimental_gc_relocate: {
+ // Translate facts known about a pointer before relocating into
+ // facts about the relocate value, while being careful to
+ // preserve relocation semantics.
+ GCRelocateOperands Operands(II);
+ Value *DerivedPtr = Operands.derivedPtr();
+
+ // Remove the relocation if unused, note that this check is required
+ // to prevent the cases below from looping forever.
+ if (II->use_empty())
+ return EraseInstFromFunction(*II);
+
+ // Undef is undef, even after relocation.
+ // TODO: provide a hook for this in GCStrategy. This is clearly legal for
+ // most practical collectors, but there was discussion in the review thread
+ // about whether it was legal for all possible collectors.
+ if (isa<UndefValue>(DerivedPtr))
+ return ReplaceInstUsesWith(*II, DerivedPtr);
+
+ // The relocation of null will be null for most any collector.
+ // TODO: provide a hook for this in GCStrategy. There might be some weird
+ // collector this property does not hold for.
+ if (isa<ConstantPointerNull>(DerivedPtr))
+ return ReplaceInstUsesWith(*II, DerivedPtr);
+
+ // isKnownNonNull -> nonnull attribute
+ if (isKnownNonNull(DerivedPtr))
+ II->addAttribute(AttributeSet::ReturnIndex, Attribute::NonNull);
+
+ // TODO: dereferenceable -> deref attribute
+
+ // TODO: bitcast(relocate(p)) -> relocate(bitcast(p))
+ // Canonicalize on the type from the uses to the defs
+
+ // TODO: relocate((gep p, C, C2, ...)) -> gep(relocate(p), C, C2, ...)
+ }
}
return visitCallSite(II);
--- /dev/null
+; RUN: opt < %s -instcombine -S | FileCheck %s
+; These tests check the optimizations specific to
+; pointers being relocated at a statepoint.
+
+
+declare void @func()
+
+define i1 @test_negative(i32 addrspace(1)* %p) {
+entry:
+ %safepoint_token = tail call i32 (void ()*, i32, i32, ...)* @llvm.experimental.gc.statepoint.p0f_isVoidf(void ()* @func, i32 0, i32 0, i32 0, i32 addrspace(1)* %p)
+ %pnew = call i32 addrspace(1)* @llvm.experimental.gc.relocate.p1i32(i32 %safepoint_token, i32 4, i32 4)
+ %cmp = icmp eq i32 addrspace(1)* %pnew, null
+ ret i1 %cmp
+; CHECK-LABEL: test_negative
+; CHECK: %pnew = call i32 addrspace(1)*
+; CHECK: ret i1 %cmp
+}
+
+define i1 @test_nonnull(i32 addrspace(1)* nonnull %p) {
+entry:
+ %safepoint_token = tail call i32 (void ()*, i32, i32, ...)* @llvm.experimental.gc.statepoint.p0f_isVoidf(void ()* @func, i32 0, i32 0, i32 0, i32 addrspace(1)* %p)
+ %pnew = call i32 addrspace(1)* @llvm.experimental.gc.relocate.p1i32(i32 %safepoint_token, i32 4, i32 4)
+ %cmp = icmp eq i32 addrspace(1)* %pnew, null
+ ret i1 %cmp
+; CHECK-LABEL: test_nonnull
+; CHECK: ret i1 false
+}
+
+define i1 @test_null() {
+entry:
+ %safepoint_token = tail call i32 (void ()*, i32, i32, ...)* @llvm.experimental.gc.statepoint.p0f_isVoidf(void ()* @func, i32 0, i32 0, i32 0, i32 addrspace(1)* null)
+ %pnew = call i32 addrspace(1)* @llvm.experimental.gc.relocate.p1i32(i32 %safepoint_token, i32 4, i32 4)
+ %cmp = icmp eq i32 addrspace(1)* %pnew, null
+ ret i1 %cmp
+; CHECK-LABEL: test_null
+; CHECK-NOT: %pnew
+; CHECK: ret i1 true
+}
+
+define i1 @test_undef() {
+entry:
+ %safepoint_token = tail call i32 (void ()*, i32, i32, ...)* @llvm.experimental.gc.statepoint.p0f_isVoidf(void ()* @func, i32 0, i32 0, i32 0, i32 addrspace(1)* undef)
+ %pnew = call i32 addrspace(1)* @llvm.experimental.gc.relocate.p1i32(i32 %safepoint_token, i32 4, i32 4)
+ %cmp = icmp eq i32 addrspace(1)* %pnew, null
+ ret i1 %cmp
+; CHECK-LABEL: test_undef
+; CHECK-NOT: %pnew
+; CHECK: ret i1 undef
+}
+
+declare i32 @llvm.experimental.gc.statepoint.p0f_isVoidf(void ()*, i32, i32, ...)
+declare i32 addrspace(1)* @llvm.experimental.gc.relocate.p1i32(i32, i32, i32) #3