[netcore] Improve Jitdiff tool (#17960)

use `objdump` arguments to reduce verbosity (no raw bytes, etc) and make the dasm more diff-friendly.
On Linux all functions have a random prefix (address) - replace it with `0xD1FFAB1E` constant). On macOS it's fine by default.

Also, allow to generate diffs for a single assembly via `dump-asm-lib` rule.

netcore/Makefile

@@ -30,6 +30,7 @@ endif
 ifeq ($(HOST_PLATFORM),macos)
 PLATFORM_AOT_SUFFIX := .dylib
 PLATFORM_AOT_PREFIX := lib
+OBJDUMP = objdump -x86-asm-syntax=intel --no-show-raw-insn -no-leading-addr -no-leading-headers -d
 NETCORESDK_EXT = tar.gz
 UNZIPCMD = tar -xvf
 XUNIT_INNER_ARGS = -notrait category=nonosxtests @../../../../CoreFX.issues_mac.rsp
@@ -40,6 +41,7 @@ endif
 ifeq ($(HOST_PLATFORM),linux)
 PLATFORM_AOT_SUFFIX := .so
 PLATFORM_AOT_PREFIX := lib
+OBJDUMP = objdump -M intel --no-show-raw-insn -d
 NETCORESDK_EXT = tar.gz
 UNZIPCMD = tar -xvf
 XUNIT_INNER_ARGS = -notrait category=nonlinuxtests @../../../../CoreFX.issues_linux.rsp
@@ -110,7 +112,7 @@ patch-local-dotnet-aot-llvm: patch-local-dotnet
 	for assembly in ../.dotnet/shared/Microsoft.NETCore.App/$(BOOTSTRAP_RUNTIME)/*.dll; do \
 		echo "[AOT] $$assembly"; \
 		PATH="../llvm/usr/bin/:$(PATH)" \
-		MONO_ENV_OPTIONS="--aot=llvm,llvmllc=\"-mcpu=native\"" \
+		MONO_ENV_OPTIONS="--aot=llvm,mcpu=native" \
 		$(DOTNET) $$assembly ; \
 	done; \
 
@@ -285,17 +287,25 @@ run-tests-coreclr-%: prepare update-tests-coreclr
 # dump asm for all methods in BCL using LLVM AOT, e.g.:
 #   make dump-asm-bcl DUMPASM_OUT=dumps/before-my-jit-fix
 dump-asm-bcl: patch-local-dotnet
-	mkdir -p $(DUMPASM_OUT)
 	@if test -z "$(DUMPASM_OUT)"; then echo "DUMPASM_OUT is not set"; exit 1; fi
+	mkdir -p $(DUMPASM_OUT)
 	for assembly in ../.dotnet/shared/Microsoft.NETCore.App/$(BOOTSTRAP_RUNTIME)/*.dll; do \
 		printf  "\n[AOT] $$(basename $$assembly):\n\n"; \
-		PATH="../llvm/usr/bin/:$(PATH)" \
-		MONO_ENV_OPTIONS="--aot=llvm,mcpu=native" \
-		$(DOTNET) $$assembly ; \
-		objdump -d "$$assembly$(PLATFORM_AOT_SUFFIX)" > "$(DUMPASM_OUT)/$$(basename $$assembly)$(PLATFORM_AOT_SUFFIX).dasm" ; \
+		$(MAKE) dump-asm-lib DUMPASM_LIB=$$assembly ; \
 	done; \
 	cd ../.dotnet/shared/Microsoft.NETCore.App/$(BOOTSTRAP_RUNTIME) && rm *.dll$(PLATFORM_AOT_SUFFIX)
 
+# dump asm for a specific assembly using LLVM AOT, e.g.:
+#   make dump-asm-lib DUMPASM_OUT=dumps/before-my-jit-fix DUMPASM_LIB=/path/to/System.Private.CoreLib.dll
+dump-asm-lib: patch-local-dotnet
+	@if test -z "$(DUMPASM_LIB)"; then echo "DUMPASM_LIB is not set"; exit 1; fi
+	@if test -z "$(DUMPASM_OUT)"; then echo "DUMPASM_OUT is not set"; exit 1; fi
+	mkdir -p $(DUMPASM_OUT)
+	PATH="../llvm/usr/bin/:$(PATH)" \
+	MONO_ENV_OPTIONS="--aot=llvm,mcpu=native" \
+	$(DOTNET) $(DUMPASM_LIB)
+	$(OBJDUMP) "$(DUMPASM_LIB)$(PLATFORM_AOT_SUFFIX)" > "$(DUMPASM_OUT)/$(notdir $(DUMPASM_LIB))$(PLATFORM_AOT_SUFFIX).dasm"
+
 # Generate asm diffs, a typical workflow may look like this:
 # 
 #   make dump-asm-bcl DUMPASM_OUT=dumps/before-my-jit-fix
@@ -310,4 +320,4 @@ jitdiff:
 	cd tools/jitdiff && $(DOTNET) run -c Release -- "$(BEFORE)" "$(AFTER)"
 
 distdir:
-distclean:
+distclean:

netcore/tools/jitdiff/jitdiff.cs

@@ -1,5 +1,6 @@
 using System;
 using System.Collections.Generic;
+using System.Text.RegularExpressions;
 using System.IO;
 using System.Linq;
 
@@ -116,7 +117,7 @@ static bool TryParseFunctionName (string str, out string name)
 			// depends on objdump, let's use the whole line as a name if it ends with `:`
 			if (str.EndsWith (':'))
 			{
-				name = str;
+				name = Regex.Replace(str, @"(?i)\b([a-f0-9]+){8,16}\b", m => "0xD1FFAB1E");
 				return true;
 			}
 			name = null;