[mlir][LLVMIR] Remove "unsafe-fp-math" attribute support (llvm#162782)

These global flags block furthur improvements for clang, users should
always use fast-math flags
see also
https://discourse.llvm.org/t/rfc-honor-pragmas-with-ffp-contract-fast/80797
Remove them incrementally, this is the mlir part.

Author: paperchalice

mlir/include/mlir/Dialect/LLVMIR/LLVMOps.td

@@ -1975,7 +1975,6 @@ def LLVM_LLVMFuncOp : LLVM_Op<"func", [
     OptionalAttr<StrAttr>:$reciprocal_estimates,
     OptionalAttr<StrAttr>:$prefer_vector_width,
     OptionalAttr<LLVM_TargetFeaturesAttr>:$target_features,
-    OptionalAttr<BoolAttr>:$unsafe_fp_math,
     OptionalAttr<BoolAttr>:$no_infs_fp_math,
     OptionalAttr<BoolAttr>:$no_nans_fp_math,
     OptionalAttr<BoolAttr>:$no_signed_zeros_fp_math,

mlir/lib/Target/LLVMIR/ModuleImport.cpp

@@ -2616,7 +2616,6 @@ static constexpr std::array kExplicitLLVMFuncOpAttributes{
     StringLiteral("optnone"),
     StringLiteral("target-features"),
     StringLiteral("tune-cpu"),
-    StringLiteral("unsafe-fp-math"),
     StringLiteral("uwtable"),
     StringLiteral("vscale_range"),
     StringLiteral("willreturn"),
@@ -2714,10 +2713,6 @@ void ModuleImport::processFunctionAttributes(llvm::Function *func,
       attr.isStringAttribute())
     funcOp.setPreferVectorWidth(attr.getValueAsString());
 
-  if (llvm::Attribute attr = func->getFnAttribute("unsafe-fp-math");
-      attr.isStringAttribute())
-    funcOp.setUnsafeFpMath(attr.getValueAsBool());
-
   if (llvm::Attribute attr = func->getFnAttribute("no-infs-fp-math");
       attr.isStringAttribute())
     funcOp.setNoInfsFpMath(attr.getValueAsBool());

mlir/lib/Target/LLVMIR/ModuleTranslation.cpp

@@ -1560,9 +1560,6 @@ LogicalResult ModuleTranslation::convertOneFunction(LLVMFuncOp func) {
         getLLVMContext(), attr->getMinRange().getInt(),
         attr->getMaxRange().getInt()));
 
-  if (auto unsafeFpMath = func.getUnsafeFpMath())
-    llvmFunc->addFnAttr("unsafe-fp-math", llvm::toStringRef(*unsafeFpMath));
-
   if (auto noInfsFpMath = func.getNoInfsFpMath())
     llvmFunc->addFnAttr("no-infs-fp-math", llvm::toStringRef(*noInfsFpMath));
 

mlir/test/Dialect/LLVMIR/func.mlir

@@ -258,12 +258,6 @@ module {
     llvm.return
   }
 
-  llvm.func @unsafe_fp_math_roundtrip() attributes {unsafe_fp_math = true} {
-    // CHECK: @unsafe_fp_math_roundtrip
-    // CHECK-SAME: attributes {unsafe_fp_math = true}
-    llvm.return
-  }
-
   llvm.func @no_infs_fp_math_roundtrip() attributes {no_infs_fp_math = true} {
     // CHECK: @no_infs_fp_math_roundtrip
     // CHECK-SAME: attributes {no_infs_fp_math = true}

mlir/test/Target/LLVMIR/Import/function-attributes.ll

@@ -303,18 +303,6 @@ declare void @align_decl() align 64
 
 ; // -----
 
-; CHECK-LABEL: @func_attr_unsafe_fp_math_true
-; CHECK-SAME: attributes {unsafe_fp_math = true}
-declare void @func_attr_unsafe_fp_math_true() "unsafe-fp-math"="true"
-
-; // -----
-
-; CHECK-LABEL: @func_attr_unsafe_fp_math_false
-; CHECK-SAME: attributes {unsafe_fp_math = false}
-declare void @func_attr_unsafe_fp_math_false() "unsafe-fp-math"="false"
-
-; // -----
-
 ; CHECK-LABEL: @func_attr_no_infs_fp_math_true
 ; CHECK-SAME: attributes {no_infs_fp_math = true}
 declare void @func_attr_no_infs_fp_math_true() "no-infs-fp-math"="true"

mlir/test/Target/LLVMIR/fp-math-function-attributes.mlir

@@ -1,23 +1,5 @@
 // RUN: mlir-translate -mlir-to-llvmir -split-input-file %s | FileCheck %s
 
-// CHECK-LABEL: define void @unsafe_fp_math_func_true()
-// CHECK-SAME: #[[ATTRS:[0-9]+]]
-llvm.func @unsafe_fp_math_func_true() attributes {unsafe_fp_math = true}  {
-  llvm.return
-}
-// CHECK: attributes #[[ATTRS]] = { "unsafe-fp-math"="true" }
-
-// -----
-
-// CHECK-LABEL: define void @unsafe_fp_math_func_false()
-// CHECK-SAME: #[[ATTRS:[0-9]+]]
-llvm.func @unsafe_fp_math_func_false() attributes {unsafe_fp_math = false}  {
-  llvm.return
-}
-// CHECK: attributes #[[ATTRS]] = { "unsafe-fp-math"="false" }
-
-// -----
-
 // CHECK-LABEL: define void @no_infs_fp_math_func_true()
 // CHECK-SAME: #[[ATTRS:[0-9]+]]
 llvm.func @no_infs_fp_math_func_true() attributes {no_infs_fp_math = true}  {