From: Zoltan Varga <vargaz@gmail.com>
Date: Thu, 10 Aug 2023 17:29:32 +0000 (-0400)
Subject: [mono][llvm] Use the OP_MEMMOVE opcode instead of calling the managed memcpy method... 
X-Git-Tag: accepted/tizen/unified/riscv/20231226.055536~373
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=3e58f554ed44a636f08eabfb1cd6b270f74c4d71;p=platform%2Fupstream%2Fdotnet%2Fruntime.git

[mono][llvm] Use the OP_MEMMOVE opcode instead of calling the managed memcpy method when compiling with LLVM. (#90097)

LLVM can emit optimized code when the length ends up being a constant.
---

diff --git a/src/mono/mono/mini/memory-access.c b/src/mono/mono/mini/memory-access.c
index 58d9c54..ceae7a3 100644
--- a/src/mono/mono/mini/memory-access.c
+++ b/src/mono/mono/mini/memory-access.c
@@ -210,7 +210,16 @@ mini_emit_memcpy_internal (MonoCompile *cfg, MonoInst *dest, MonoInst *src, Mono
 		if (!size_ins)
 			EMIT_NEW_ICONST (cfg, size_ins, size);
 		iargs [2] = size_ins;
-		mono_emit_method_call (cfg, mini_get_memcpy_method (), iargs, NULL);
+		if (COMPILE_LLVM (cfg)) {
+			MonoInst *ins;
+			MONO_INST_NEW (cfg, ins, OP_MEMMOVE);
+			ins->sreg1 = iargs [0]->dreg;
+			ins->sreg2 = iargs [1]->dreg;
+			ins->sreg3 = iargs [2]->dreg;
+			MONO_ADD_INS (cfg->cbb, ins);
+		} else {
+			mono_emit_method_call (cfg, mini_get_memcpy_method (), iargs, NULL);
+		}
 	} else {
 		mini_emit_memcpy (cfg, dest->dreg, 0, src->dreg, 0, size, align);
 	}