[llvm] ARM: Move abi name implied float abi to TargetParser (PR #226774)

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llvmorg-github-actions[bot] wrote:


<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-backend-arm

Author: Matt Arsenault (arsenm)

<details>
<summary>Changes</summary>

ARMTargetMachine overrode the default float abi based on the abi name.
Move this logic to TargetParser so the ABI will be computable without
depending on codegen.

Co-Authored-By: Claude Sonnet 5 <noreply@<!-- -->anthropic.com>

---
Full diff: https://github.com/llvm/llvm-project/pull/226774.diff


3 Files Affected:

- (modified) llvm/include/llvm/TargetParser/Triple.h (+4-2) 
- (modified) llvm/lib/Target/ARM/ARMTargetMachine.cpp (+1-8) 
- (modified) llvm/lib/TargetParser/Triple.cpp (+6-4) 


``````````diff
diff --git a/llvm/include/llvm/TargetParser/Triple.h b/llvm/include/llvm/TargetParser/Triple.h
index b369b66960b1a..e161fd0f00eb9 100644
--- a/llvm/include/llvm/TargetParser/Triple.h
+++ b/llvm/include/llvm/TargetParser/Triple.h
@@ -1258,8 +1258,10 @@ class Triple {
   }
 
   /// Returns the default floating-point ABI for this target triple, i.e. the
-  /// ABI the code generator will resolve FloatABI::Default to
-  LLVM_ABI FloatABI::ABIType getDefaultFloatABI() const;
+  /// ABI the code generator will resolve FloatABI::Default to. \p ABIName, if
+  /// given, is the effective target ABI (e.g. "aapcs16" can force hard float on
+  /// ARM even when the ordinary default is soft).
+  LLVM_ABI FloatABI::ABIType getDefaultFloatABI(StringRef ABIName = "") const;
 
   /// Tests if the target's default floating-point ABI is hard float.
   bool isHardFloatABI() const { return getDefaultFloatABI() == FloatABI::Hard; }
diff --git a/llvm/lib/Target/ARM/ARMTargetMachine.cpp b/llvm/lib/Target/ARM/ARMTargetMachine.cpp
index e1153ed22ab91..6bc7cd019e0f5 100644
--- a/llvm/lib/Target/ARM/ARMTargetMachine.cpp
+++ b/llvm/lib/Target/ARM/ARMTargetMachine.cpp
@@ -219,14 +219,7 @@ FloatABI::ABIType ARMBaseTargetMachine::getFloatABI(const Module &M) const {
   // An explicit "float-abi" module flag always wins, even for AAPCS16.
   if (auto *Val = dyn_cast_or_null<MDString>(M.getModuleFlag("float-abi")))
     return *FloatABI::parseABIType(Val->getString());
-
-  // With no explicit ABI, an explicit -target-abi=aapcs16 forces hard float
-  // even on triples whose default float ABI is soft (the triple default only
-  // detects AAPCS16 when it is the triple's own default ABI).
-  if (getEffectiveABI(M) == ARM::ARM_ABI_AAPCS16)
-    return FloatABI::Hard;
-  // Otherwise fall back to the ABI implied by the target triple.
-  return M.getTargetTriple().getDefaultFloatABI();
+  return M.getTargetTriple().getDefaultFloatABI(getTargetABIName(M));
 }
 
 ARM::ARMABI ARMBaseTargetMachine::getEffectiveABI(const Module &M) const {
diff --git a/llvm/lib/TargetParser/Triple.cpp b/llvm/lib/TargetParser/Triple.cpp
index 6f2c867a318d2..ef480281700f4 100644
--- a/llvm/lib/TargetParser/Triple.cpp
+++ b/llvm/lib/TargetParser/Triple.cpp
@@ -2518,19 +2518,21 @@ ExceptionHandling Triple::getDefaultExceptionHandling() const {
   return ExceptionHandling::None;
 }
 
-static FloatABI::ABIType getARMDefaultFloatABI(const Triple &T) {
+static FloatABI::ABIType getARMDefaultFloatABI(const Triple &T,
+                                               StringRef ABIName) {
   Triple::EnvironmentType Env = T.getEnvironment();
   bool IsHard =
       Env == Triple::GNUEABIHF || Env == Triple::GNUEABIHFT64 ||
       Env == Triple::MuslEABIHF || Env == Triple::EABIHF ||
       (T.isOSBinFormatMachO() && T.getSubArch() == Triple::ARMSubArch_v7em) ||
-      T.isOSWindows() || ARM::computeTargetABI(T, "") == ARM::ARM_ABI_AAPCS16;
+      T.isOSWindows() ||
+      ARM::computeTargetABI(T, ABIName) == ARM::ARM_ABI_AAPCS16;
   return IsHard ? FloatABI::Hard : FloatABI::Soft;
 }
 
-FloatABI::ABIType Triple::getDefaultFloatABI() const {
+FloatABI::ABIType Triple::getDefaultFloatABI(StringRef ABIName) const {
   if (isARM() || isThumb())
-    return getARMDefaultFloatABI(*this);
+    return getARMDefaultFloatABI(*this, ABIName);
 
   // MIPS defaults to hard float, except on FreeBSD which uses soft float.
   if (isMIPS())

``````````

</details>


https://github.com/llvm/llvm-project/pull/226774