TableGen: Add !size operation

Summary:
Returns the size of a list. I have found this to be rather useful in some
development for the AMDGPU backend where we could simplify our .td files
by concatenating list<LLVMType> for complex intrinsics. Doing so requires
us to compute the position argument for LLVMMatchType.

Basically, the usage is in a pattern that looks somewhat like this:

    list<LLVMType> argtypes =
        !listconcat(base,
                    [llvm_any_ty, LLVMMatchType<!size(base)>]);

Change-Id: I360a0b000fd488d18bea412228230fd93722bd2c

Reviewers: arsenm, craig.topper, tra, MartinO

Subscribers: wdng, llvm-commits, tpr

Differential Revision: https://reviews.llvm.org/D43553

llvm-svn: 325883

1 files changed, 34 insertions, 0 deletions

diff --git a/llvm/test/TableGen/size.td b/llvm/test/TableGen/size.td
new file mode 100644
index 00000000000..f7061e11079
--- /dev/null
+++ b/llvm/test/TableGen/size.td
@@ -0,0 +1,34 @@
+// RUN: llvm-tblgen %s | FileCheck %s
+// XFAIL: vg_leak
+
+// CHECK: --- Defs ---
+
+// CHECK: def A1 {
+// CHECK:   int Val = 0;
+// CHECK: }
+
+// CHECK: def A2 {
+// CHECK:   int Val = 3;
+// CHECK: }
+
+// CHECK: def B1 {
+// CHECK:   int Val = 0;
+// CHECK: }
+
+// CHECK: def B2 {
+// CHECK:   int Val = 2;
+// CHECK: }
+
+class A<list<int> L> {
+  int Val = !size(L);
+}
+
+class B<list<string> L> {
+  int Val = !size(L);
+}
+
+def A1 : A<[]>;
+def A2 : A<[1, 1, 2]>;
+
+def B1 : B<[]>;
+def B2 : B<["a", "b"]>;