From 3376ff2d67191d260d44a42f751ee25353e61adb Mon Sep 17 00:00:00 2001
From: Jay Krell <jay.krell@cornell.edu>
Date: Mon, 30 Apr 2018 14:25:27 -0700
Subject: [PATCH] [Tailcall PowerPC] OP_TAILCALL_PARAMETER support. (#8500)

---
 mono/mini/cpu-ppc.md | 4 ++++
 mono/mini/mini-ppc.c | 7 +++++++
 2 files changed, 11 insertions(+)

diff --git a/mono/mini/cpu-ppc.md b/mono/mini/cpu-ppc.md
index dc5d587ab1d..5eea6e3cf9d 100644
--- a/mono/mini/cpu-ppc.md
+++ b/mono/mini/cpu-ppc.md
@@ -52,6 +52,10 @@ break: len:32
 seq_point: len:24
 il_seq_point: len:0
 tailcall: len:120 clob:c
+
+# PowerPC outputs a nice fixed size memcpy loop for larger stack_usage, so 0.
+tailcall_parameter: len:0
+
 call: dest:a clob:c len:16
 br: len:4
 throw: src1:i len:20
diff --git a/mono/mini/mini-ppc.c b/mono/mini/mini-ppc.c
index 76677a95955..e02d37187a4 100644
--- a/mono/mini/mini-ppc.c
+++ b/mono/mini/mini-ppc.c
@@ -3816,6 +3816,13 @@ mono_arch_output_basic_block (MonoCompile *cfg, MonoBasicBlock *bb)
 		case OP_FCONV_TO_R4:
 			ppc_frsp (code, ins->dreg, ins->sreg1);
 			break;
+
+		case OP_TAILCALL_PARAMETER:
+			// This opcode helps compute sizes, i.e.
+			// of the subsequent OP_TAILCALL, but contributes no code.
+			g_assert (ins->next);
+			break;
+
 		case OP_TAILCALL: {
 			int i, pos;
 			MonoCallInst *call = (MonoCallInst*)ins;
-- 
2.11.4.GIT