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[flang] optimize cosd precision #154955

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Merged
merged 1 commit into from
Aug 25, 2025
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[flang] optimize cosd precision #154955

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9 changes: 5 additions & 4 deletions flang/lib/Optimizer/Builder/IntrinsicCall.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -3707,10 +3707,11 @@ mlir::Value IntrinsicLibrary::genCosd(mlir::Type resultType,
mlir::MLIRContext *context = builder.getContext();
mlir::FunctionType ftype =
mlir::FunctionType::get(context, {resultType}, {args[0].getType()});
llvm::APFloat pi = llvm::APFloat(llvm::numbers::pi);
mlir::Value dfactor = builder.createRealConstant(
loc, mlir::Float64Type::get(context), pi / llvm::APFloat(180.0));
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, pi / llvm::APFloat(fltSem, "180.0"));
mlir::Value arg = mlir::arith::MulFOp::create(builder, loc, args[0], factor);
return getRuntimeCallGenerator("cos", ftype)(builder, loc, {arg});
}
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14 changes: 12 additions & 2 deletions flang/test/Lower/Intrinsics/cosd.f90
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@@ -1,3 +1,4 @@
! REQUIRES: flang-supports-f128-math
! RUN: bbc -emit-fir %s -o - | FileCheck %s --check-prefixes="CHECK,CHECK-FAST"
! RUN: bbc --math-runtime=precise -emit-fir %s -o - | FileCheck %s --check-prefixes="CHECK,CHECK-PRECISE"
! RUN: %flang_fc1 -emit-fir %s -o - | FileCheck %s --check-prefixes="CHECK,CHECK-FAST"
Expand All @@ -8,8 +9,7 @@ function test_real4(x)
end function

! CHECK-LABEL: @_QPtest_real4
! CHECK: %[[dfactor:.*]] = arith.constant 0.017453292519943295 : f64
! CHECK: %[[factor:.*]] = fir.convert %[[dfactor]] : (f64) -> f32
! CHECK: %[[factor:.*]] = arith.constant 0.0174532924 : f32
! CHECK: %[[arg:.*]] = arith.mulf %{{[A-Za-z0-9._]+}}, %[[factor]] fastmath<contract> : f32
! CHECK-PRECISE: %{{.*}} = fir.call @cosf(%[[arg]]) fastmath<contract> : (f32) -> f32
! CHECK-FAST: %{{.*}} = math.cos %[[arg]] fastmath<contract> : f32
Expand All @@ -24,3 +24,13 @@ function test_real8(x)
! CHECK: %[[arg:.*]] = arith.mulf %{{[A-Za-z0-9._]+}}, %[[factor]] fastmath<contract> : f64
! CHECK-PRECISE: %{{.*}} = fir.call @cos(%[[arg]]) fastmath<contract> : (f64) -> f64
! CHECK-FAST: %{{.*}} = math.cos %[[arg]] fastmath<contract> : f64

function test_real16(x)
real(16) :: x, test_real16
test_real16 = cosd(x)
end function

! CHECK-LABEL: @_QPtest_real16
! CHECK: %[[factor:.*]] = arith.constant 0.0174532925199432957692369076848861{{.*}} : f128
! CHECK: %[[arg:.*]] = arith.mulf %{{[A-Za-z0-9._]+}}, %[[factor]] fastmath<contract> : f128
! CHECK: %[[result:.*]] = fir.call @_FortranACosF128({{.*}}) fastmath<contract> : (f128) -> f128