[clang] [llvm] [WebAssembly] Add half-precision feature (PR #90248)
Brendan Dahl via llvm-commits
llvm-commits at lists.llvm.org
Fri Apr 26 13:28:06 PDT 2024
https://github.com/brendandahl updated https://github.com/llvm/llvm-project/pull/90248
>From 85e5e1660ad1e6fda8ecf8984aab0cba96130b4f Mon Sep 17 00:00:00 2001
From: Brendan Dahl <brendan.dahl at gmail.com>
Date: Fri, 26 Apr 2024 18:30:48 +0000
Subject: [PATCH] [WebAssembly] Add half-precision feature
This currently only defines a constant, but in the future will be used
to gate builtins for experimenting and prototyping half-precision proposal
(https://github.com/WebAssembly/half-precision).
---
clang/include/clang/Driver/Options.td | 2 ++
clang/lib/Basic/Targets/WebAssembly.cpp | 11 +++++++++++
clang/lib/Basic/Targets/WebAssembly.h | 1 +
clang/test/Driver/wasm-features.c | 6 ++++++
llvm/lib/Target/WebAssembly/WebAssembly.td | 3 +++
llvm/lib/Target/WebAssembly/WebAssemblyInstrInfo.td | 4 ++++
llvm/lib/Target/WebAssembly/WebAssemblySubtarget.h | 2 ++
7 files changed, 29 insertions(+)
diff --git a/clang/include/clang/Driver/Options.td b/clang/include/clang/Driver/Options.td
index 922bda721dc780..0a3c4494443cad 100644
--- a/clang/include/clang/Driver/Options.td
+++ b/clang/include/clang/Driver/Options.td
@@ -4876,6 +4876,8 @@ def msimd128 : Flag<["-"], "msimd128">, Group<m_wasm_Features_Group>;
def mno_simd128 : Flag<["-"], "mno-simd128">, Group<m_wasm_Features_Group>;
def mrelaxed_simd : Flag<["-"], "mrelaxed-simd">, Group<m_wasm_Features_Group>;
def mno_relaxed_simd : Flag<["-"], "mno-relaxed-simd">, Group<m_wasm_Features_Group>;
+def mhalf_precision : Flag<["-"], "mhalf-precision">, Group<m_wasm_Features_Group>;
+def mno_half_precision : Flag<["-"], "mno-half-precision">, Group<m_wasm_Features_Group>;
def mnontrapping_fptoint : Flag<["-"], "mnontrapping-fptoint">, Group<m_wasm_Features_Group>;
def mno_nontrapping_fptoint : Flag<["-"], "mno-nontrapping-fptoint">, Group<m_wasm_Features_Group>;
def msign_ext : Flag<["-"], "msign-ext">, Group<m_wasm_Features_Group>;
diff --git a/clang/lib/Basic/Targets/WebAssembly.cpp b/clang/lib/Basic/Targets/WebAssembly.cpp
index d473fd19086460..3d76411f890a86 100644
--- a/clang/lib/Basic/Targets/WebAssembly.cpp
+++ b/clang/lib/Basic/Targets/WebAssembly.cpp
@@ -47,6 +47,7 @@ bool WebAssemblyTargetInfo::hasFeature(StringRef Feature) const {
return llvm::StringSwitch<bool>(Feature)
.Case("simd128", SIMDLevel >= SIMD128)
.Case("relaxed-simd", SIMDLevel >= RelaxedSIMD)
+ .Case("half-precision", HasHalfPrecision)
.Case("nontrapping-fptoint", HasNontrappingFPToInt)
.Case("sign-ext", HasSignExt)
.Case("exception-handling", HasExceptionHandling)
@@ -156,6 +157,7 @@ bool WebAssemblyTargetInfo::initFeatureMap(
Features["reference-types"] = true;
Features["sign-ext"] = true;
Features["tail-call"] = true;
+ Features["half-precision"] = true;
setSIMDLevel(Features, SIMD128, true);
} else if (CPU == "generic") {
Features["mutable-globals"] = true;
@@ -216,6 +218,15 @@ bool WebAssemblyTargetInfo::handleTargetFeatures(
HasBulkMemory = false;
continue;
}
+ if (Feature == "+half-precision") {
+ SIMDLevel = std::max(SIMDLevel, SIMD128);
+ HasHalfPrecision = true;
+ continue;
+ }
+ if (Feature == "-half-precision") {
+ HasHalfPrecision = false;
+ continue;
+ }
if (Feature == "+atomics") {
HasAtomics = true;
continue;
diff --git a/clang/lib/Basic/Targets/WebAssembly.h b/clang/lib/Basic/Targets/WebAssembly.h
index 5568aa28eaefa7..e4c18879182ed7 100644
--- a/clang/lib/Basic/Targets/WebAssembly.h
+++ b/clang/lib/Basic/Targets/WebAssembly.h
@@ -64,6 +64,7 @@ class LLVM_LIBRARY_VISIBILITY WebAssemblyTargetInfo : public TargetInfo {
bool HasReferenceTypes = false;
bool HasExtendedConst = false;
bool HasMultiMemory = false;
+ bool HasHalfPrecision = false;
std::string ABI;
diff --git a/clang/test/Driver/wasm-features.c b/clang/test/Driver/wasm-features.c
index 5dae5dbc89b905..1f7fb213498265 100644
--- a/clang/test/Driver/wasm-features.c
+++ b/clang/test/Driver/wasm-features.c
@@ -77,6 +77,12 @@
// RELAXED-SIMD: "-target-feature" "+relaxed-simd"
// NO-RELAXED-SIMD: "-target-feature" "-relaxed-simd"
+// RUN: %clang --target=wasm32-unknown-unknown -### %s -mhalf-precision 2>&1 | FileCheck %s -check-prefix=HALF-PRECISION
+// RUN: %clang --target=wasm32-unknown-unknown -### %s -mno-half-precision 2>&1 | FileCheck %s -check-prefix=NO-HALF-PRECISION
+
+// HALF-PRECISION: "-target-feature" "+half-precision"
+// NO-HALF-PRECISION: "-target-feature" "-half-precision"
+
// RUN: %clang --target=wasm32-unknown-unknown -### %s -mexception-handling 2>&1 | FileCheck %s -check-prefix=EXCEPTION-HANDLING
// RUN: %clang --target=wasm32-unknown-unknown -### %s -mno-exception-handling 2>&1 | FileCheck %s -check-prefix=NO-EXCEPTION-HANDLING
diff --git a/llvm/lib/Target/WebAssembly/WebAssembly.td b/llvm/lib/Target/WebAssembly/WebAssembly.td
index d538197450b65b..f00974531209d2 100644
--- a/llvm/lib/Target/WebAssembly/WebAssembly.td
+++ b/llvm/lib/Target/WebAssembly/WebAssembly.td
@@ -28,6 +28,9 @@ def FeatureSIMD128 : SubtargetFeature<"simd128", "SIMDLevel", "SIMD128",
def FeatureRelaxedSIMD : SubtargetFeature<"relaxed-simd", "SIMDLevel", "RelaxedSIMD",
"Enable relaxed-simd instructions">;
+def FeatureHalfPrecision : SubtargetFeature<"half-precision", "HasHalfPrecision", "true",
+ "Enable half precision instructions">;
+
def FeatureAtomics : SubtargetFeature<"atomics", "HasAtomics", "true",
"Enable Atomics">;
diff --git a/llvm/lib/Target/WebAssembly/WebAssemblyInstrInfo.td b/llvm/lib/Target/WebAssembly/WebAssemblyInstrInfo.td
index 59ea9247bd86f5..7b57f8ce90e066 100644
--- a/llvm/lib/Target/WebAssembly/WebAssemblyInstrInfo.td
+++ b/llvm/lib/Target/WebAssembly/WebAssemblyInstrInfo.td
@@ -30,6 +30,10 @@ def HasRelaxedSIMD :
Predicate<"Subtarget->hasRelaxedSIMD()">,
AssemblerPredicate<(all_of FeatureRelaxedSIMD), "relaxed-simd">;
+def HasHalfPrecision :
+ Predicate<"Subtarget->hasHalfPrecision()">,
+ AssemblerPredicate<(all_of FeatureHalfPrecision), "half-precision">;
+
def HasAtomics :
Predicate<"Subtarget->hasAtomics()">,
AssemblerPredicate<(all_of FeatureAtomics), "atomics">;
diff --git a/llvm/lib/Target/WebAssembly/WebAssemblySubtarget.h b/llvm/lib/Target/WebAssembly/WebAssemblySubtarget.h
index 85d02b087c786e..8b0d9fa12de8f3 100644
--- a/llvm/lib/Target/WebAssembly/WebAssemblySubtarget.h
+++ b/llvm/lib/Target/WebAssembly/WebAssemblySubtarget.h
@@ -50,6 +50,7 @@ class WebAssemblySubtarget final : public WebAssemblyGenSubtargetInfo {
bool HasReferenceTypes = false;
bool HasExtendedConst = false;
bool HasMultiMemory = false;
+ bool HasHalfPrecision = false;
/// What processor and OS we're targeting.
Triple TargetTriple;
@@ -93,6 +94,7 @@ class WebAssemblySubtarget final : public WebAssemblyGenSubtargetInfo {
bool hasAddr64() const { return TargetTriple.isArch64Bit(); }
bool hasSIMD128() const { return SIMDLevel >= SIMD128; }
bool hasRelaxedSIMD() const { return SIMDLevel >= RelaxedSIMD; }
+ bool hasHalfPrecision() const { return HasHalfPrecision; }
bool hasAtomics() const { return HasAtomics; }
bool hasNontrappingFPToInt() const { return HasNontrappingFPToInt; }
bool hasSignExt() const { return HasSignExt; }
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