[PATCH] D88610: Correct kP scaling on F output

[Peter Klausler via Phabricator via llvm-commits]

klausler created this revision.
klausler added a reviewer: sscalpone.
klausler added a project: Flang.
Herald added a reviewer: jdoerfert.
Herald added a project: LLVM.
Herald added a subscriber: llvm-commits.
klausler requested review of this revision.

The sign of the scaling factor was misinterpreted for output
as meaning what it does for input.  To be correct, they
should cancel each other out.

print '(1P,F4 <https://reviews.llvm.org/F4>.3)', 1. ! printed 0.1 but should print 10.0


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D88610

Files:
  flang/runtime/edit-output.cpp
  flang/unittests/Runtime/hello.cpp


Index: flang/unittests/Runtime/hello.cpp
===================================================================
--- flang/unittests/Runtime/hello.cpp
+++ flang/unittests/Runtime/hello.cpp
@@ -197,7 +197,7 @@
       {"(G32.17E4,';')", "        1.0000000000000000      ;"},
       {"(1P,E32.17,';')", "         1.00000000000000000E+00;"},
       {"(1PE32.17,';')", "         1.00000000000000000E+00;"}, // no comma
-      {"(1P,F32.17,';')", "             0.10000000000000000;"},
+      {"(1P,F32.17,';')", "            10.00000000000000000;"},
       {"(1P,G32.17,';')", "          1.0000000000000000    ;"},
       {"(ES32.17,';')", "         1.00000000000000000E+00;"},
       {"(2P,E32.17,';')", "         10.0000000000000000E-01;"},
Index: flang/runtime/edit-output.cpp
===================================================================
--- flang/runtime/edit-output.cpp
+++ flang/runtime/edit-output.cpp
@@ -278,8 +278,8 @@
       return EmitPrefix(edit, converted.length, editWidth) &&
           io_.Emit(converted.str, converted.length) && EmitSuffix(edit);
     }
-    int scale{IsZero() ? -1 : edit.modes.scale};
-    int expo{converted.decimalExponent - scale};
+    int scale{IsZero() ? 1 : edit.modes.scale}; // kP
+    int expo{converted.decimalExponent + scale};
     if (expo > extraDigits && extraDigits >= 0) {
       extraDigits = expo;
       if (!edit.digits.has_value()) { // F0


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