[flang-commits] [flang] [flang] Register and lower SECNDS (stubbed implementation) (PR #151878)

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llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->
@llvm/pr-subscribers-flang-fir-hlfir

@llvm/pr-subscribers-flang-semantics

Author: Šárka Holendová (mlir-maiden)

<details>
<summary>Changes</summary>

This patch registers and lowers the GNU extension intrinsic `SECNDS` in Flang.

- Registration and lowering are wired through the intrinsic infrastructure.
- genSecnds() currently emits a TODO fatal error, marking it as unimplemented.
- Includes an XFAIL test to exercise the lowering path and reflect current status.


### TODOs:
- Implement runtime behavior for `SECNDS`
---

CC @<!-- -->eugeneepshteyn @<!-- -->klausler 

---
Full diff: https://github.com/llvm/llvm-project/pull/151878.diff


4 Files Affected:

- (modified) flang/include/flang/Optimizer/Builder/IntrinsicCall.h (+2) 
- (modified) flang/lib/Evaluate/intrinsics.cpp (+5) 
- (modified) flang/lib/Optimizer/Builder/IntrinsicCall.cpp (+12) 
- (added) flang/test/Lower/Intrinsics/secnds.f90 (+12) 


``````````diff
diff --git a/flang/include/flang/Optimizer/Builder/IntrinsicCall.h b/flang/include/flang/Optimizer/Builder/IntrinsicCall.h
index d38c5b6d09a82..62ecd6c8a53f1 100644
--- a/flang/include/flang/Optimizer/Builder/IntrinsicCall.h
+++ b/flang/include/flang/Optimizer/Builder/IntrinsicCall.h
@@ -401,6 +401,8 @@ struct IntrinsicLibrary {
                                    llvm::ArrayRef<fir::ExtendedValue>);
   mlir::Value genScale(mlir::Type, llvm::ArrayRef<mlir::Value>);
   fir::ExtendedValue genScan(mlir::Type, llvm::ArrayRef<fir::ExtendedValue>);
+  fir::ExtendedValue genSecnds(mlir::Type resultType,
+                               llvm::ArrayRef<fir::ExtendedValue> args);
   fir::ExtendedValue genSecond(std::optional<mlir::Type>,
                                mlir::ArrayRef<fir::ExtendedValue>);
   fir::ExtendedValue genSelectedCharKind(mlir::Type,
diff --git a/flang/lib/Evaluate/intrinsics.cpp b/flang/lib/Evaluate/intrinsics.cpp
index 4773e136c41cb..634154d994c25 100644
--- a/flang/lib/Evaluate/intrinsics.cpp
+++ b/flang/lib/Evaluate/intrinsics.cpp
@@ -918,6 +918,11 @@ static const IntrinsicInterface genericIntrinsicFunction[]{
             {"back", AnyLogical, Rank::elemental, Optionality::optional},
             DefaultingKIND},
         KINDInt},
+    {"secnds",
+        {{"x", TypePattern{RealType, KindCode::exactKind, 4}, Rank::scalar,
+            Optionality::required, common::Intent::In}},
+        TypePattern{RealType, KindCode::exactKind, 4}, Rank::scalar,
+        IntrinsicClass::impureSubroutine},
     {"second", {}, DefaultReal, Rank::scalar},
     {"selected_char_kind", {{"name", DefaultChar, Rank::scalar}}, DefaultInt,
         Rank::scalar, IntrinsicClass::transformationalFunction},
diff --git a/flang/lib/Optimizer/Builder/IntrinsicCall.cpp b/flang/lib/Optimizer/Builder/IntrinsicCall.cpp
index 8d0a511744e25..9b037cc66c59e 100644
--- a/flang/lib/Optimizer/Builder/IntrinsicCall.cpp
+++ b/flang/lib/Optimizer/Builder/IntrinsicCall.cpp
@@ -852,6 +852,10 @@ static constexpr IntrinsicHandler handlers[]{
        {"back", asValue, handleDynamicOptional},
        {"kind", asValue}}},
      /*isElemental=*/true},
+    {"secnds",
+     &I::genSecnds,
+     {{{"x", asValue}}},
+     /*isElemental=*/false},
     {"second",
      &I::genSecond,
      {{{"time", asAddr}}},
@@ -7722,6 +7726,14 @@ IntrinsicLibrary::genScan(mlir::Type resultType,
   return readAndAddCleanUp(resultMutableBox, resultType, "SCAN");
 }
 
+// SECNDS
+// Lowering is registered, runtime not yet implemented
+fir::ExtendedValue
+IntrinsicLibrary::genSecnds(mlir::Type resultType,
+                            llvm::ArrayRef<fir::ExtendedValue> args) {
+  TODO(loc, "not yet implemented: SECNDS");
+}
+
 // SECOND
 fir::ExtendedValue
 IntrinsicLibrary::genSecond(std::optional<mlir::Type> resultType,
diff --git a/flang/test/Lower/Intrinsics/secnds.f90 b/flang/test/Lower/Intrinsics/secnds.f90
new file mode 100644
index 0000000000000..105e93ad9301e
--- /dev/null
+++ b/flang/test/Lower/Intrinsics/secnds.f90
@@ -0,0 +1,12 @@
+!---------------------------------------------------------------------
+! RUN: %flang_fc1 -emit-fir %s -o - 2>&1 | FileCheck %s
+! XFAIL: *
+!---------------------------------------------------------------------
+
+program test_secnds
+  real :: x
+  x = secnds(1.0)
+end program
+
+! CHECK: not yet implemented: SECNDS
+

``````````

</details>


https://github.com/llvm/llvm-project/pull/151878