[clang] [lld] [llvm] [WebAssembly] Enable nontrapping-fptoint and bulk-memory by default. (PR #112049)

Dan Gohman via cfe-commits cfe-commits at lists.llvm.org
Tue Oct 15 16:49:01 PDT 2024


https://github.com/sunfishcode updated https://github.com/llvm/llvm-project/pull/112049

>From 7d55b35158ceb1a5d35ac62ecfe404f6a374e526 Mon Sep 17 00:00:00 2001
From: Dan Gohman <dev at sunfishcode.online>
Date: Fri, 11 Oct 2024 13:31:13 -0700
Subject: [PATCH 1/5] [WebAssembly] Enable nontrapping-fptoint and bulk-memory
 by default.

We were prepared to enable these features [back in February], but they
got pulled for what appear to be unrelated reasons. So let's have another
try at enabling them!

Another motivation here is that it'd be convenient for the
[Trail1 proposal] if "trail1" is a superset of "generic".

[back in February]: https://github.com/WebAssembly/tool-conventions/issues/158#issuecomment-1931119512
[Trail1 proposal]: https://github.com/llvm/llvm-project/pull/112035
---
 clang/docs/ReleaseNotes.rst                | 9 +++++++++
 clang/lib/Basic/Targets/WebAssembly.cpp    | 2 ++
 llvm/docs/ReleaseNotes.md                  | 9 +++++++++
 llvm/lib/Target/WebAssembly/WebAssembly.td | 3 ++-
 4 files changed, 22 insertions(+), 1 deletion(-)

diff --git a/clang/docs/ReleaseNotes.rst b/clang/docs/ReleaseNotes.rst
index 36cf1d8a14db9f..60eeb7f72647cf 100644
--- a/clang/docs/ReleaseNotes.rst
+++ b/clang/docs/ReleaseNotes.rst
@@ -630,6 +630,15 @@ NetBSD Support
 WebAssembly Support
 ^^^^^^^^^^^^^^^^^^^
 
+The default target CPU, "generic", now enables the `-mnontrapping-fptoint`
+and `-mbulk-memory` flags, which correspond to the [Bulk Memory Operations]
+and [Non-trapping float-to-int Conversions] language features, which are
+[widely implemented in engines].
+
+[Bulk Memory Operations]: https://github.com/WebAssembly/bulk-memory-operations/blob/master/proposals/bulk-memory-operations/Overview.md
+[Non-trapping float-to-int Conversions]: https://github.com/WebAssembly/spec/blob/master/proposals/nontrapping-float-to-int-conversion/Overview.md
+[widely implemented in engines]: https://webassembly.org/features/
+
 AVR Support
 ^^^^^^^^^^^
 
diff --git a/clang/lib/Basic/Targets/WebAssembly.cpp b/clang/lib/Basic/Targets/WebAssembly.cpp
index 5ac9421663adea..1ac8f14f8cb175 100644
--- a/clang/lib/Basic/Targets/WebAssembly.cpp
+++ b/clang/lib/Basic/Targets/WebAssembly.cpp
@@ -151,8 +151,10 @@ bool WebAssemblyTargetInfo::initFeatureMap(
     llvm::StringMap<bool> &Features, DiagnosticsEngine &Diags, StringRef CPU,
     const std::vector<std::string> &FeaturesVec) const {
   auto addGenericFeatures = [&]() {
+    Features["bulk-memory"] = true;
     Features["multivalue"] = true;
     Features["mutable-globals"] = true;
+    Features["nontrapping-fptoint"] = true;
     Features["reference-types"] = true;
     Features["sign-ext"] = true;
   };
diff --git a/llvm/docs/ReleaseNotes.md b/llvm/docs/ReleaseNotes.md
index 6e37852b4574ed..49218465cbc0dc 100644
--- a/llvm/docs/ReleaseNotes.md
+++ b/llvm/docs/ReleaseNotes.md
@@ -169,6 +169,15 @@ Changes to the RISC-V Backend
 Changes to the WebAssembly Backend
 ----------------------------------
 
+The default target CPU, "generic", now enables the `-mnontrapping-fptoint`
+and `-mbulk-memory` flags, which correspond to the [Bulk Memory Operations]
+and [Non-trapping float-to-int Conversions] language features, which are
+[widely implemented in engines].
+
+[Bulk Memory Operations]: https://github.com/WebAssembly/bulk-memory-operations/blob/master/proposals/bulk-memory-operations/Overview.md
+[Non-trapping float-to-int Conversions]: https://github.com/WebAssembly/spec/blob/master/proposals/nontrapping-float-to-int-conversion/Overview.md
+[widely implemented in engines]: https://webassembly.org/features/
+
 Changes to the Windows Target
 -----------------------------
 
diff --git a/llvm/lib/Target/WebAssembly/WebAssembly.td b/llvm/lib/Target/WebAssembly/WebAssembly.td
index c632d4a74355d8..1e22707db23e91 100644
--- a/llvm/lib/Target/WebAssembly/WebAssembly.td
+++ b/llvm/lib/Target/WebAssembly/WebAssembly.td
@@ -110,7 +110,8 @@ def : ProcessorModel<"mvp", NoSchedModel, []>;
 // consideration given to available support in relevant engines and tools, and
 // the importance of the features.
 def : ProcessorModel<"generic", NoSchedModel,
-                      [FeatureMultivalue, FeatureMutableGlobals,
+                      [FeatureBulkMemory, FeatureMultivalue,
+                       FeatureMutableGlobals, FeatureNontrappingFPToInt,
                        FeatureReferenceTypes, FeatureSignExt]>;
 
 // Latest and greatest experimental version of WebAssembly. Bugs included!

>From 84dfea09fac4bedcd4d5e7780deb498e10190d76 Mon Sep 17 00:00:00 2001
From: Dan Gohman <dev at sunfishcode.online>
Date: Fri, 11 Oct 2024 16:58:39 -0700
Subject: [PATCH 2/5] Update tests.

---
 .../test/CodeGen/WebAssembly/cfg-stackify-eh-legacy.ll | 10 +++++-----
 llvm/test/CodeGen/WebAssembly/target-features-cpus.ll  |  8 +++++++-
 llvm/test/MC/WebAssembly/extern-functype-intrinsic.ll  |  4 ++--
 llvm/test/MC/WebAssembly/libcall.ll                    |  2 +-
 4 files changed, 15 insertions(+), 9 deletions(-)

diff --git a/llvm/test/CodeGen/WebAssembly/cfg-stackify-eh-legacy.ll b/llvm/test/CodeGen/WebAssembly/cfg-stackify-eh-legacy.ll
index cef92f459e4aa3..24a08267db6fbf 100644
--- a/llvm/test/CodeGen/WebAssembly/cfg-stackify-eh-legacy.ll
+++ b/llvm/test/CodeGen/WebAssembly/cfg-stackify-eh-legacy.ll
@@ -1,9 +1,9 @@
 ; REQUIRES: asserts
-; RUN: llc < %s -disable-wasm-fallthrough-return-opt -wasm-disable-explicit-locals -wasm-keep-registers -disable-block-placement -verify-machineinstrs -fast-isel=false -machine-sink-split-probability-threshold=0 -cgp-freq-ratio-to-skip-merge=1000 -wasm-enable-eh -exception-model=wasm -mattr=+exception-handling | FileCheck %s
-; RUN: llc < %s -disable-wasm-fallthrough-return-opt -disable-block-placement -verify-machineinstrs -fast-isel=false -machine-sink-split-probability-threshold=0 -cgp-freq-ratio-to-skip-merge=1000 -wasm-enable-eh -exception-model=wasm -mattr=+exception-handling
-; RUN: llc < %s -O0 -disable-wasm-fallthrough-return-opt -wasm-disable-explicit-locals -wasm-keep-registers -verify-machineinstrs -wasm-enable-eh -exception-model=wasm -mattr=+exception-handling | FileCheck %s --check-prefix=NOOPT
-; RUN: llc < %s -disable-wasm-fallthrough-return-opt -wasm-disable-explicit-locals -wasm-keep-registers -disable-block-placement -verify-machineinstrs -fast-isel=false -machine-sink-split-probability-threshold=0 -cgp-freq-ratio-to-skip-merge=1000 -wasm-enable-eh -exception-model=wasm -mattr=+exception-handling -wasm-disable-ehpad-sort -stats 2>&1 | FileCheck %s --check-prefix=NOSORT
-; RUN: llc < %s -disable-wasm-fallthrough-return-opt -disable-block-placement -verify-machineinstrs -fast-isel=false -machine-sink-split-probability-threshold=0 -cgp-freq-ratio-to-skip-merge=1000 -wasm-enable-eh -exception-model=wasm -mattr=+exception-handling -wasm-disable-ehpad-sort | FileCheck %s --check-prefix=NOSORT-LOCALS
+; RUN: llc < %s -disable-wasm-fallthrough-return-opt -wasm-disable-explicit-locals -wasm-keep-registers -disable-block-placement -verify-machineinstrs -fast-isel=false -machine-sink-split-probability-threshold=0 -cgp-freq-ratio-to-skip-merge=1000 -wasm-enable-eh -exception-model=wasm -mattr=+exception-handling,bulk-memory | FileCheck %s
+; RUN: llc < %s -disable-wasm-fallthrough-return-opt -disable-block-placement -verify-machineinstrs -fast-isel=false -machine-sink-split-probability-threshold=0 -cgp-freq-ratio-to-skip-merge=1000 -wasm-enable-eh -exception-model=wasm -mattr=+exception-handling,bulk-memory
+; RUN: llc < %s -O0 -disable-wasm-fallthrough-return-opt -wasm-disable-explicit-locals -wasm-keep-registers -verify-machineinstrs -wasm-enable-eh -exception-model=wasm -mattr=+exception-handling,-bulk-memory | FileCheck %s --check-prefix=NOOPT
+; RUN: llc < %s -disable-wasm-fallthrough-return-opt -wasm-disable-explicit-locals -wasm-keep-registers -disable-block-placement -verify-machineinstrs -fast-isel=false -machine-sink-split-probability-threshold=0 -cgp-freq-ratio-to-skip-merge=1000 -wasm-enable-eh -exception-model=wasm -mattr=+exception-handling,-bulk-memory -wasm-disable-ehpad-sort -stats 2>&1 | FileCheck %s --check-prefix=NOSORT
+; RUN: llc < %s -disable-wasm-fallthrough-return-opt -disable-block-placement -verify-machineinstrs -fast-isel=false -machine-sink-split-probability-threshold=0 -cgp-freq-ratio-to-skip-merge=1000 -wasm-enable-eh -exception-model=wasm -mattr=+exception-handling,-bulk-memory -wasm-disable-ehpad-sort | FileCheck %s --check-prefix=NOSORT-LOCALS
 
 target triple = "wasm32-unknown-unknown"
 
diff --git a/llvm/test/CodeGen/WebAssembly/target-features-cpus.ll b/llvm/test/CodeGen/WebAssembly/target-features-cpus.ll
index 77d1564409f78c..ba10dd94a9838d 100644
--- a/llvm/test/CodeGen/WebAssembly/target-features-cpus.ll
+++ b/llvm/test/CodeGen/WebAssembly/target-features-cpus.ll
@@ -13,7 +13,10 @@ target triple = "wasm32-unknown-unknown"
 
 ; generic: +multivalue, +mutable-globals, +reference-types, +sign-ext
 ; GENERIC-LABEL: .custom_section.target_features,"",@
-; GENERIC-NEXT: .int8  4
+; GENERIC-NEXT: .int8  6
+; GENERIC-NEXT: .int8  43
+; GENERIC-NEXT: .int8  11
+; GENERIC-NEXT: .ascii  "bulk-memory"
 ; GENERIC-NEXT: .int8  43
 ; GENERIC-NEXT: .int8  10
 ; GENERIC-NEXT: .ascii  "multivalue"
@@ -21,6 +24,9 @@ target triple = "wasm32-unknown-unknown"
 ; GENERIC-NEXT: .int8  15
 ; GENERIC-NEXT: .ascii  "mutable-globals"
 ; GENERIC-NEXT: .int8  43
+; GENERIC-NEXT: .int8  19
+; GENERIC-NEXT: .ascii  "nontrapping-fptoint"
+; GENERIC-NEXT: .int8  43
 ; GENERIC-NEXT: .int8  15
 ; GENERIC-NEXT: .ascii  "reference-types"
 ; GENERIC-NEXT: .int8  43
diff --git a/llvm/test/MC/WebAssembly/extern-functype-intrinsic.ll b/llvm/test/MC/WebAssembly/extern-functype-intrinsic.ll
index 320b65356ba9f3..b321c0c82ad4d3 100644
--- a/llvm/test/MC/WebAssembly/extern-functype-intrinsic.ll
+++ b/llvm/test/MC/WebAssembly/extern-functype-intrinsic.ll
@@ -1,5 +1,5 @@
-; RUN: llc %s -o - | FileCheck %s
-; RUN: llc %s -o - | llvm-mc -triple=wasm32-unknown-unknown | FileCheck %s
+; RUN: llc %s -mattr=-bulk-memory -o - | FileCheck %s
+; RUN: llc %s -mattr=-bulk-memory -o - | llvm-mc -triple=wasm32-unknown-unknown | FileCheck %s
 
 ; ModuleID = 'test.c'
 source_filename = "test.c"
diff --git a/llvm/test/MC/WebAssembly/libcall.ll b/llvm/test/MC/WebAssembly/libcall.ll
index 8b81f150da892a..ffd32abe2345bc 100644
--- a/llvm/test/MC/WebAssembly/libcall.ll
+++ b/llvm/test/MC/WebAssembly/libcall.ll
@@ -1,4 +1,4 @@
-; RUN: llc -filetype=obj %s -o - | obj2yaml | FileCheck %s
+; RUN: llc -filetype=obj -mattr=-bulk-memory %s -o - | obj2yaml | FileCheck %s
 
 target triple = "wasm32-unknown-unknown"
 

>From 26b8333e0dad6d8489a379d187483a8d1b86c3e2 Mon Sep 17 00:00:00 2001
From: Dan Gohman <dev at sunfishcode.online>
Date: Mon, 14 Oct 2024 03:11:45 -0700
Subject: [PATCH 3/5] Update tests.

---
 clang/test/Preprocessor/wasm-target-features.c | 4 ++--
 lld/test/wasm/custom-section-name.ll           | 2 +-
 lld/test/wasm/data-segments.ll                 | 2 +-
 lld/test/wasm/lto/libcall-archive.ll           | 2 +-
 lld/test/wasm/lto/stub-library-libcall.s       | 2 +-
 5 files changed, 6 insertions(+), 6 deletions(-)

diff --git a/clang/test/Preprocessor/wasm-target-features.c b/clang/test/Preprocessor/wasm-target-features.c
index c64d3a0aa22825..f1b13c03757ee3 100644
--- a/clang/test/Preprocessor/wasm-target-features.c
+++ b/clang/test/Preprocessor/wasm-target-features.c
@@ -166,6 +166,8 @@
 // GENERIC-INCLUDE-DAG: #define __wasm_mutable_globals__ 1{{$}}
 // GENERIC-INCLUDE-DAG: #define __wasm_reference_types__ 1{{$}}
 // GENERIC-INCLUDE-DAG: #define __wasm_sign_ext__ 1{{$}}
+// GENERIC-INCLUDE-DAG: #define __wasm_nontrapping_fptoint__ 1{{$}}
+// GENERIC-INCLUDE-DAG: #define __wasm_bulk_memory__ 1{{$}}
 //
 // RUN: %clang -E -dM %s -o - 2>&1 \
 // RUN:     -target wasm32-unknown-unknown -mcpu=generic \
@@ -175,12 +177,10 @@
 // RUN:   | FileCheck %s -check-prefix=GENERIC
 //
 // GENERIC-NOT: #define __wasm_atomics__ 1{{$}}
-// GENERIC-NOT: #define __wasm_bulk_memory__ 1{{$}}
 // GENERIC-NOT: #define __wasm_exception_handling__ 1{{$}}
 // GENERIC-NOT: #define __wasm_extended_const__ 1{{$}}
 // GENERIC-NOT: #define __wasm__fp16__ 1{{$}}
 // GENERIC-NOT: #define __wasm_multimemory__ 1{{$}}
-// GENERIC-NOT: #define __wasm_nontrapping_fptoint__ 1{{$}}
 // GENERIC-NOT: #define __wasm_relaxed_simd__ 1{{$}}
 // GENERIC-NOT: #define __wasm_simd128__ 1{{$}}
 // GENERIC-NOT: #define __wasm_tail_call__ 1{{$}}
diff --git a/lld/test/wasm/custom-section-name.ll b/lld/test/wasm/custom-section-name.ll
index b860ef5a83e836..8799fbf36056d1 100644
--- a/lld/test/wasm/custom-section-name.ll
+++ b/lld/test/wasm/custom-section-name.ll
@@ -1,4 +1,4 @@
-; RUN: llc -filetype=obj %s -o %t.o
+; RUN: llc -filetype=obj -mattr=-bulk-memory %s -o %t.o
 ; RUN: wasm-ld -no-gc-sections --no-entry -o %t.wasm %t.o
 ; RUN: obj2yaml %t.wasm | FileCheck %s --check-prefixes=CHECK,NO-BSS
 ; RUN: wasm-ld -no-gc-sections --no-entry --import-memory -o %t.bss.wasm %t.o
diff --git a/lld/test/wasm/data-segments.ll b/lld/test/wasm/data-segments.ll
index 670ac3c1f373fa..41868a0b2b50b6 100644
--- a/lld/test/wasm/data-segments.ll
+++ b/lld/test/wasm/data-segments.ll
@@ -1,4 +1,4 @@
-; RUN: llc --mtriple=wasm32-unknown-unknown -filetype=obj %s -o %t.atomics.o -mattr=+atomics
+; RUN: llc --mtriple=wasm32-unknown-unknown -filetype=obj %s -o %t.atomics.o -mattr=+atomics,-bulk-memory
 ; RUN: llc --mtriple=wasm32-unknown-unknown -filetype=obj %s -o %t.bulk-mem.o -mattr=+bulk-memory
 ; RUN: llc --mtriple=wasm64-unknown-unknown -filetype=obj %s -o %t.bulk-mem64.o -mattr=+bulk-memory
 ; RUN: llc --mtriple=wasm32-unknown-unknown -filetype=obj %s -o %t.atomics.bulk-mem.o -mattr=+atomics,+bulk-memory
diff --git a/lld/test/wasm/lto/libcall-archive.ll b/lld/test/wasm/lto/libcall-archive.ll
index 365ce180f1441e..078faaa782dd93 100644
--- a/lld/test/wasm/lto/libcall-archive.ll
+++ b/lld/test/wasm/lto/libcall-archive.ll
@@ -2,7 +2,7 @@
 ; RUN: llvm-as -o %t.o %s
 ; RUN: llvm-as -o %t2.o %S/Inputs/libcall-archive.ll
 ; RUN: llvm-ar rcs %t.a %t2.o
-; RUN: wasm-ld -o %t %t.o %t.a
+; RUN: wasm-ld -mllvm -mattr=-bulk-memory -o %t %t.o %t.a
 ; RUN: obj2yaml %t | FileCheck %s
 
 target datalayout = "e-m:e-p:32:32-p10:8:8-p20:8:8-i64:64-n32:64-S128"
diff --git a/lld/test/wasm/lto/stub-library-libcall.s b/lld/test/wasm/lto/stub-library-libcall.s
index ce88a32dd99dc7..3ae4b1ec0a5c2c 100644
--- a/lld/test/wasm/lto/stub-library-libcall.s
+++ b/lld/test/wasm/lto/stub-library-libcall.s
@@ -2,7 +2,7 @@
 # RUN: llvm-mc -filetype=obj -triple=wasm32-unknown-unknown -o %t_main.o %t/main.s
 # RUN: llvm-as %S/Inputs/foo.ll -o %t_foo.o
 # RUN: llvm-as %S/Inputs/libcall.ll -o %t_libcall.o
-# RUN: wasm-ld %t_main.o %t_libcall.o %t_foo.o %p/Inputs/stub.so -o %t.wasm
+# RUN: wasm-ld -mllvm -mattr=-bulk-memory %t_main.o %t_libcall.o %t_foo.o %p/Inputs/stub.so -o %t.wasm
 # RUN: obj2yaml %t.wasm | FileCheck %s
 
 # The function `func_with_libcall` will generate an undefined reference to

>From 4283395bb5e3ec8ca83ee453beb4eba76c1dc269 Mon Sep 17 00:00:00 2001
From: Dan Gohman <dev at sunfishcode.online>
Date: Mon, 14 Oct 2024 04:11:51 -0700
Subject: [PATCH 4/5] Update tests.

---
 lld/test/wasm/lto/stub-library-libcall.s | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/lld/test/wasm/lto/stub-library-libcall.s b/lld/test/wasm/lto/stub-library-libcall.s
index 3ae4b1ec0a5c2c..d65983c0cf5bf5 100644
--- a/lld/test/wasm/lto/stub-library-libcall.s
+++ b/lld/test/wasm/lto/stub-library-libcall.s
@@ -12,7 +12,7 @@
 # If %t_foo.o is not included in the link we get an undefined symbol reported
 # to the dependency of memcpy on the foo export:
 
-# RUN: not wasm-ld %t_main.o %t_libcall.o %p/Inputs/stub.so -o %t.wasm 2>&1 | FileCheck --check-prefix=MISSING %s
+# RUN: not wasm-ld -mllvm -mattr=-bulk-memory %t_main.o %t_libcall.o %p/Inputs/stub.so -o %t.wasm 2>&1 | FileCheck --check-prefix=MISSING %s
 # MISSING: stub.so: undefined symbol: foo. Required by memcpy
 
 #--- main.s

>From b4f8335ff4d58b46206247a231fd6caa73be8604 Mon Sep 17 00:00:00 2001
From: Dan Gohman <dev at sunfishcode.online>
Date: Tue, 15 Oct 2024 16:48:12 -0700
Subject: [PATCH 5/5] Move `-bulk-memory` flags from wasm-ld flags to a
 function attributes.

---
 lld/test/wasm/lto/Inputs/libcall-archive.ll | 4 +++-
 lld/test/wasm/lto/libcall-archive.ll        | 6 ++++--
 2 files changed, 7 insertions(+), 3 deletions(-)

diff --git a/lld/test/wasm/lto/Inputs/libcall-archive.ll b/lld/test/wasm/lto/Inputs/libcall-archive.ll
index def1452bdf35cf..0317415d2faae4 100644
--- a/lld/test/wasm/lto/Inputs/libcall-archive.ll
+++ b/lld/test/wasm/lto/Inputs/libcall-archive.ll
@@ -1,6 +1,8 @@
 target datalayout = "e-m:e-p:32:32-p10:8:8-p20:8:8-i64:64-n32:64-S128"
 target triple = "wasm32-unknown-unknown"
 
-define void @memcpy() {
+define void @memcpy() #0 {
   ret void
 }
+
+attributes #0 = { "target-features"="-bulk-memory" }
diff --git a/lld/test/wasm/lto/libcall-archive.ll b/lld/test/wasm/lto/libcall-archive.ll
index 078faaa782dd93..4bfe7cf7471ef3 100644
--- a/lld/test/wasm/lto/libcall-archive.ll
+++ b/lld/test/wasm/lto/libcall-archive.ll
@@ -2,13 +2,13 @@
 ; RUN: llvm-as -o %t.o %s
 ; RUN: llvm-as -o %t2.o %S/Inputs/libcall-archive.ll
 ; RUN: llvm-ar rcs %t.a %t2.o
-; RUN: wasm-ld -mllvm -mattr=-bulk-memory -o %t %t.o %t.a
+; RUN: wasm-ld -o %t %t.o %t.a
 ; RUN: obj2yaml %t | FileCheck %s
 
 target datalayout = "e-m:e-p:32:32-p10:8:8-p20:8:8-i64:64-n32:64-S128"
 target triple = "wasm32-unknown-unknown"
 
-define void @_start(ptr %a, ptr %b) {
+define void @_start(ptr %a, ptr %b) #0 {
 entry:
   call void @llvm.memcpy.p0.p0.i64(ptr %a, ptr %b, i64 1024, i1 false)
   ret void
@@ -16,6 +16,8 @@ entry:
 
 declare void @llvm.memcpy.p0.p0.i64(ptr nocapture, ptr nocapture, i64, i1)
 
+attributes #0 = { "target-features"="-bulk-memory" }
+
 ; CHECK:       - Type:            CUSTOM
 ; CHECK-NEXT:    Name:            name
 ; CHECK-NEXT:    FunctionNames:



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