[builtins] Divide shouldn't underflow if rounded result would be normal.
We were treating certain edge cases that are actually normal as denormal
results, and flushing them to zero; we shouldn't do that. Not sure this
is the cleanest way to implement this edge case, but I wanted to avoid
adding any code on the common path.
Differential Revision: https://reviews.llvm.org/D59070
llvm-svn: 356529
diff --git a/compiler-rt/test/builtins/Unit/divsf3_test.c b/compiler-rt/test/builtins/Unit/divsf3_test.c
new file mode 100644
index 0000000..4b14c81
--- /dev/null
+++ b/compiler-rt/test/builtins/Unit/divsf3_test.c
@@ -0,0 +1,45 @@
+// RUN: %clang_builtins %s %librt -o %t && %run %t
+//===--------------- divsf3_test.c - Test __divsf3 ------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+//
+// This file tests __divsf3 for the compiler_rt library.
+//
+//===----------------------------------------------------------------------===//
+
+#include "int_lib.h"
+#include <stdio.h>
+
+#include "fp_test.h"
+
+// Returns: a / b
+COMPILER_RT_ABI float __divsf3(float a, float b);
+
+int test__divsf3(float a, float b, uint32_t expected)
+{
+ float x = __divsf3(a, b);
+ int ret = compareResultF(x, expected);
+
+ if (ret){
+ printf("error in test__divsf3(%.20e, %.20e) = %.20e, "
+ "expected %.20e\n", a, b, x,
+ fromRep32(expected));
+ }
+ return ret;
+}
+
+int main()
+{
+ // 1/3
+ if (test__divsf3(1.f, 3.f, 0x3EAAAAABU))
+ return 1;
+ // smallest normal result
+ if (test__divsf3(2.3509887e-38, 2., 0x00800000U))
+ return 1;
+
+ return 0;
+}