From 43f078aedc88dc707e34b8c283b8ac59714d1a50 Mon Sep 17 00:00:00 2001
From: gingerBill <gingerBill@users.noreply.github.com>
Date: Wed, 12 Aug 2026 14:52:37 +0100
Subject: [PATCH] Infer `asm #side_effects` where possible from the mnemonics

---
 .../isa/x86/tablegen/cpp-compiler/cpp-gen.odin      | 13 ++++++++++++-
 src/asm_tables_amd64.cpp                            | 13 ++++++++++++-
 src/llvm_backend_asm.cpp                            |  9 +++------
 3 files changed, 27 insertions(+), 8 deletions(-)

diff --git a/core/rexcode/isa/x86/tablegen/cpp-compiler/cpp-gen.odin b/core/rexcode/isa/x86/tablegen/cpp-compiler/cpp-gen.odin
index cb23e4666..e6a8a863f 100644
--- a/core/rexcode/isa/x86/tablegen/cpp-compiler/cpp-gen.odin
+++ b/core/rexcode/isa/x86/tablegen/cpp-compiler/cpp-gen.odin
@@ -200,7 +200,18 @@ main :: proc() {
 		strings.write_string(&sb, "\t\t\t\t                 SideEffectFlag_SERIALIZING)) != 0;\n")
 		strings.write_string(&sb, "\t\t}\n")
 		strings.write_string(&sb, "\t\tbool implies_side_effects() {\n")
-		strings.write_string(&sb, "\t\t\treturn side_effects;\n")
+		strings.write_string(&sb, "\t\t\tu16 const VOLATILE_SE =\n")
+		strings.write_string(&sb, "\t\t\t\tSideEffectFlag_FENCE       |\n")
+		strings.write_string(&sb, "\t\t\t\tSideEffectFlag_SERIALIZING |\n")
+		strings.write_string(&sb, "\t\t\t\tSideEffectFlag_CACHE       |\n")
+		strings.write_string(&sb, "\t\t\t\tSideEffectFlag_TRAP        |\n")
+		strings.write_string(&sb, "\t\t\t\tSideEffectFlag_INTERRUPT   |\n")
+		strings.write_string(&sb, "\t\t\t\tSideEffectFlag_HALT        |\n")
+		strings.write_string(&sb, "\t\t\t\tSideEffectFlag_PRIVILEGED  |\n")
+		strings.write_string(&sb, "\t\t\t\tSideEffectFlag_CONTROL     |\n")
+		strings.write_string(&sb, "\t\t\t\tSideEffectFlag_CET;\n")
+		strings.write_string(&sb, "\t\t\t\t// NOTE: SideEffectFlag_HINT deliberately excluded — inert, may be DCE'd.\n")
+		strings.write_string(&sb, "\t\t\treturn ((side_effects & VOLATILE_SE) != 0);\n")
 		strings.write_string(&sb, "\t\t}\n")
 		strings.write_string(&sb, "\t};\n")
 	}
diff --git a/src/asm_tables_amd64.cpp b/src/asm_tables_amd64.cpp
index f35abb5d3..8151ad8a4 100644
--- a/src/asm_tables_amd64.cpp
+++ b/src/asm_tables_amd64.cpp
@@ -205,7 +205,18 @@ struct Asm_amd64 {
 				                 SideEffectFlag_SERIALIZING)) != 0;
 		}
 		bool implies_side_effects() {
-			return side_effects;
+			u16 const VOLATILE_SE =
+				SideEffectFlag_FENCE       |
+				SideEffectFlag_SERIALIZING |
+				SideEffectFlag_CACHE       |
+				SideEffectFlag_TRAP        |
+				SideEffectFlag_INTERRUPT   |
+				SideEffectFlag_HALT        |
+				SideEffectFlag_PRIVILEGED  |
+				SideEffectFlag_CONTROL     |
+				SideEffectFlag_CET;
+				// NOTE: SideEffectFlag_HINT deliberately excluded — inert, may be DCE'd.
+			return ((side_effects & VOLATILE_SE) != 0);
 		}
 	};
 
diff --git a/src/llvm_backend_asm.cpp b/src/llvm_backend_asm.cpp
index 1803489b9..406622921 100644
--- a/src/llvm_backend_asm.cpp
+++ b/src/llvm_backend_asm.cpp
@@ -480,21 +480,18 @@ struct lbAsmGenerate_amd64 : lbAsmGenerate {
 
 		LLVMTypeRef fn_ty = LLVMFunctionType(ret_ty, param_types.data, cast(unsigned)param_types.count, /*vararg*/false);
 
-		// TODO(bill): determine all the cases when side-effects happen
-		bool has_side_effects = tmpl_node->has_side_effects;
-
 		LLVMValueRef ia = LLVMGetInlineAsm(
 			fn_ty,
 			asm_string,  cast(size_t)gb_string_length(asm_string),
 			constraints, cast(size_t)gb_string_length(constraints),
-			/*HasSideEffects*/ has_side_effects,
-			/*IsAlignStack*/   tmpl_node->is_align_stack,
+			/*HasSideEffects*/ tmpl_entity->AsmTemplate.has_side_effects,
+			/*IsAlignStack*/   tmpl_entity->AsmTemplate.is_align_stack,
 			LLVMInlineAsmDialectATT,
 			/*CanThrow*/       false);
 
 		LLVMValueRef call = LLVMBuildCall2(p->builder, fn_ty, ia, call_args.data, cast(unsigned)call_args.count, "");
 
-		if (false) {
+		if (true) {
 			// DEBUG PRINT!!!
 			// DEBUG PRINT!!!
 			// DEBUG PRINT!!!