Don't pass -fno-inline-functions when -Oz/-Os are used (#17843)

We have no reason not to let clang use its own heuristics here.

As a followup we can consider completely removing the `INLINGING_LIMIT`
setting since it no longer serves any purpose other than to set this
clang flag.

Author: sbc100

ChangeLog.md

@@ -21,6 +21,9 @@ See docs/process.md for more on how version tagging works.
 3.1.22 (in development)
 -----------------------
 - compiler-rt updated to LLVM 15. (#17802)
+- Using `-Oz` or `-Os` will no longer pass `-fno-inline-functions` to clang and
+  instead rely on clang's normal inline heuristics for these optimization
+  levels.  `-fno-inline-functions` can be passed explicitly if needed.
 
 3.1.21 - 09/09/2022
 -------------------

emcc.py

@@ -3160,11 +3160,9 @@ def consume_arg_file():
       if options.requested_level == 's':
         options.requested_level = 2
         settings.SHRINK_LEVEL = 1
-        settings_changes.append('INLINING_LIMIT=1')
       elif options.requested_level == 'z':
         options.requested_level = 2
         settings.SHRINK_LEVEL = 2
-        settings_changes.append('INLINING_LIMIT=1')
       settings.OPT_LEVEL = validate_arg_level(options.requested_level, 3, 'invalid optimization level: ' + arg, clamp=True)
     elif check_arg('--js-opts'):
       logger.warning('--js-opts ignored when using llvm backend')

test/code_size/hello_webgl2_wasm.json

@@ -2,9 +2,9 @@
   "a.html": 569,
   "a.html.gz": 379,
   "a.js": 4968,
-  "a.js.gz": 2427,
-  "a.wasm": 10418,
-  "a.wasm.gz": 6674,
-  "total": 15955,
-  "total_gz": 9480
+  "a.js.gz": 2428,
+  "a.wasm": 10446,
+  "a.wasm.gz": 6675,
+  "total": 15983,
+  "total_gz": 9482
 }

test/code_size/hello_webgl2_wasm2js.json

@@ -1,10 +1,10 @@
 {
   "a.html": 567,
   "a.html.gz": 379,
-  "a.js": 18045,
-  "a.js.gz": 7991,
+  "a.js": 18065,
+  "a.js.gz": 7983,
   "a.mem": 3171,
   "a.mem.gz": 2714,
-  "total": 21783,
-  "total_gz": 11084
+  "total": 21803,
+  "total_gz": 11076
 }

test/code_size/hello_webgl_wasm.json

@@ -3,8 +3,8 @@
   "a.html.gz": 379,
   "a.js": 4447,
   "a.js.gz": 2247,
-  "a.wasm": 10418,
-  "a.wasm.gz": 6674,
-  "total": 15434,
-  "total_gz": 9300
+  "a.wasm": 10446,
+  "a.wasm.gz": 6675,
+  "total": 15462,
+  "total_gz": 9301
 }

test/code_size/hello_webgl_wasm2js.json

@@ -1,10 +1,10 @@
 {
   "a.html": 567,
   "a.html.gz": 379,
-  "a.js": 17517,
-  "a.js.gz": 7821,
+  "a.js": 17536,
+  "a.js.gz": 7833,
   "a.mem": 3171,
   "a.mem.gz": 2714,
-  "total": 21255,
-  "total_gz": 10914
+  "total": 21274,
+  "total_gz": 10926
 }

test/other/metadce/test_metadce_cxx_ctors1.size

@@ -1 +1 @@
-122337
+122342

test/other/metadce/test_metadce_cxx_ctors2.size

@@ -1 +1 @@
-122238
+122243

test/other/metadce/test_metadce_cxx_except.size

@@ -1 +1 @@
-163779
+163784

test/other/metadce/test_metadce_cxx_except_wasm.size

@@ -1 +1 @@
-135733
+135738