[flang-commits] [flang] a0eb995 - [flang] optimize `asind` precision (#154350)

[via flang-commits]

Author: Connector Switch
Date: 2025-08-19T23:54:09+08:00
New Revision: a0eb9958eb05593895f19d708b09040f60e1e822

URL: https://github.com/llvm/llvm-project/commit/a0eb9958eb05593895f19d708b09040f60e1e822
DIFF: https://github.com/llvm/llvm-project/commit/a0eb9958eb05593895f19d708b09040f60e1e822.diff

LOG: [flang] optimize `asind` precision (#154350)

Part of https://github.com/llvm/llvm-project/issues/150452.

Added: 
    

Modified: 
    flang/lib/Optimizer/Builder/IntrinsicCall.cpp
    flang/test/Lower/Intrinsics/asind.f90

Removed: 
    


################################################################################
diff  --git a/flang/lib/Optimizer/Builder/IntrinsicCall.cpp b/flang/lib/Optimizer/Builder/IntrinsicCall.cpp
index 22193f0de88a1..bc3086e28f751 100644
--- a/flang/lib/Optimizer/Builder/IntrinsicCall.cpp
+++ b/flang/lib/Optimizer/Builder/IntrinsicCall.cpp
@@ -2841,10 +2841,11 @@ mlir::Value IntrinsicLibrary::genAsind(mlir::Type resultType,
       mlir::FunctionType::get(context, {resultType}, {args[0].getType()});
   mlir::Value result =
       getRuntimeCallGenerator("asin", ftype)(builder, loc, {args[0]});
-  llvm::APFloat pi = llvm::APFloat(llvm::numbers::pi);
-  mlir::Value dfactor = builder.createRealConstant(
-      loc, mlir::Float64Type::get(context), llvm::APFloat(180.0) / pi);
-  mlir::Value factor = builder.createConvert(loc, args[0].getType(), dfactor);
+  const llvm::fltSemantics &fltSem =
+      llvm::cast<mlir::FloatType>(resultType).getFloatSemantics();
+  llvm::APFloat pi = llvm::APFloat(fltSem, llvm::numbers::pis);
+  mlir::Value factor = builder.createRealConstant(
+      loc, resultType, llvm::APFloat(fltSem, "180.0") / pi);
   return mlir::arith::MulFOp::create(builder, loc, result, factor);
 }
 

diff  --git a/flang/test/Lower/Intrinsics/asind.f90 b/flang/test/Lower/Intrinsics/asind.f90
index 564fa955fa969..8d6198f53e4b4 100644
--- a/flang/test/Lower/Intrinsics/asind.f90
+++ b/flang/test/Lower/Intrinsics/asind.f90
@@ -1,3 +1,4 @@
+! REQUIRES: flang-supports-f128-math
 ! RUN: %flang_fc1 -emit-fir %s -o - | FileCheck %s --check-prefixes="CHECK"
 
 function test_real4(x)
@@ -6,9 +7,8 @@ function test_real4(x)
 end function
 
 ! CHECK-LABEL: @_QPtest_real4
-! CHECK: %[[dfactor:.*]] = arith.constant 57.295779513082323 : f64
+! CHECK: %[[factor:.*]] = arith.constant 57.2957763 : f32
 ! CHECK: %[[result:.*]] = math.asin %{{.*}} fastmath<contract> : f32
-! CHECK: %[[factor:.*]] = fir.convert %[[dfactor]] : (f64) -> f32
 ! CHECK: %[[arg:.*]] = arith.mulf %[[result]], %[[factor]] fastmath<contract> : f32
 
 function test_real8(x)
@@ -17,6 +17,16 @@ function test_real8(x)
 end function
 
 ! CHECK-LABEL: @_QPtest_real8
-! CHECK: %[[dfactor:.*]] = arith.constant 57.295779513082323 : f64
+! CHECK: %[[factor:.*]] = arith.constant 57.295779513082323 : f64
 ! CHECK: %[[result:.*]] = math.asin %{{.*}} fastmath<contract> : f64
-! CHECK: %[[arg:.*]] = arith.mulf %[[result]], %[[dfactor]] fastmath<contract> : f64
+! CHECK: %[[arg:.*]] = arith.mulf %[[result]], %[[factor]] fastmath<contract> : f64
+
+function test_real16(x)
+  real(16) :: x, test_real16
+  test_real16 = asind(x)
+end function
+
+! CHECK-LABEL: @_QPtest_real16
+! CHECK: %[[factor:.*]] = arith.constant 57.295779513082320876798154814105{{.*}} : f128
+! CHECK: %[[result:.*]] = fir.call @_FortranAAsinF128({{.*}}) fastmath<contract> : (f128) -> f128
+! CHECK: %[[arg:.*]] = arith.mulf %[[result]], %[[factor]] fastmath<contract> : f128