Revert "[compiler-rt][ARM] Optimized mulsf3 and divsf3"

[statham-arm]

Reverts #161546

One of the buildbots reported a cmake error I don't understand, and which I didn't get in my own test builds:

CMake Error at /var/lib/buildbot/fuchsia-x86_64-linux/llvm-project/compiler-rt/cmake/Modules/CheckAssemblerFlag.cmake:23 (try_compile):
  COMPILE_DEFINITIONS specified on a srcdir type TRY_COMPILE

My best guess is that the thing I did in CheckAssemblerFlag.cmake only works on some versions of cmake. But I don't understand the problem well enough to fix it quickly, so I'm reverting the whole patch and will reland it later.

[github-actions]

⚠️ C/C++ code formatter, clang-format found issues in your code. ⚠️

You can test this locally with the following command:

git-clang-format --diff origin/main HEAD --extensions c -- compiler-rt/test/builtins/Unit/divsf3_test.c --diff_from_common_commit

⚠️
The reproduction instructions above might return results for more than one PR
in a stack if you are using a stacked PR workflow. You can limit the results by
changing origin/main to the base branch/commit you want to compare against.
⚠️

View the diff from clang-format here.

diff --git a/compiler-rt/test/builtins/Unit/divsf3_test.c b/compiler-rt/test/builtins/Unit/divsf3_test.c
index f8cb6169a..e4a227976 100644
--- a/compiler-rt/test/builtins/Unit/divsf3_test.c
+++ b/compiler-rt/test/builtins/Unit/divsf3_test.c
@@ -9,107 +9,105 @@
 // 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 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()
-{
-    // Returned NaNs are assumed to be qNaN by default
-
-    // qNaN / any = qNaN
-    if (test__divsf3(makeQNaN32(), 3.F, UINT32_C(0x7fc00000)))
-      return 1;
-    // NaN / any = NaN
-    if (test__divsf3(makeNaN32(UINT32_C(0x123)), 3.F, UINT32_C(0x7fc00000)))
-      return 1;
-    // any / qNaN = qNaN
-    if (test__divsf3(3.F, makeQNaN32(), UINT32_C(0x7fc00000)))
-      return 1;
-    // any / NaN = NaN
-    if (test__divsf3(3.F, makeNaN32(UINT32_C(0x123)), UINT32_C(0x7fc00000)))
-      return 1;
-
-    // +Inf / positive = +Inf
-    if (test__divsf3(makeInf32(), 3.F, UINT32_C(0x7f800000)))
-      return 1;
-    // +Inf / negative = -Inf
-    if (test__divsf3(makeInf32(), -3.F, UINT32_C(0xff800000)))
-      return 1;
-    // -Inf / positive = -Inf
-    if (test__divsf3(makeNegativeInf32(), 3.F, UINT32_C(0xff800000)))
-      return 1;
-    // -Inf / negative = +Inf
-    if (test__divsf3(makeNegativeInf32(), -3.F, UINT32_C(0x7f800000)))
-      return 1;
-
-    // Inf / Inf = NaN
-    if (test__divsf3(makeInf32(), makeInf32(), UINT32_C(0x7fc00000)))
-      return 1;
-    // 0.0 / 0.0 = NaN
-    if (test__divsf3(+0x0.0p+0F, +0x0.0p+0F, UINT32_C(0x7fc00000)))
-      return 1;
-    // +0.0 / +Inf = +0.0
-    if (test__divsf3(+0x0.0p+0F, makeInf32(), UINT32_C(0x0)))
-      return 1;
-    // +Inf / +0.0 = +Inf
-    if (test__divsf3(makeInf32(), +0x0.0p+0F, UINT32_C(0x7f800000)))
-      return 1;
-
-    // positive / +0.0 = +Inf
-    if (test__divsf3(+1.F, +0x0.0p+0F, UINT32_C(0x7f800000)))
-      return 1;
-    // positive / -0.0 = -Inf
-    if (test__divsf3(+1.F, -0x0.0p+0F, UINT32_C(0xff800000)))
-      return 1;
-    // negative / +0.0 = -Inf
-    if (test__divsf3(-1.F, +0x0.0p+0F, UINT32_C(0xff800000)))
-      return 1;
-    // negative / -0.0 = +Inf
-    if (test__divsf3(-1.F, -0x0.0p+0F, UINT32_C(0x7f800000)))
-      return 1;
-
-    // 1/3
-    if (test__divsf3(1.F, 3.F, UINT32_C(0x3eaaaaab)))
-      return 1;
-    // smallest normal result
-    if (test__divsf3(0x1.0p-125F, 2.F, UINT32_C(0x00800000)))
-      return 1;
-
-    // divisor is exactly 1.0
-    if (test__divsf3(0x1.0p+0F, 0x1.0p+0F, UINT32_C(0x3f800000)))
-      return 1;
-    // divisor is truncated to exactly 1.0 in UQ1.15
-    if (test__divsf3(0x1.0p+0F, 0x1.0001p+0F, UINT32_C(0x3f7fff00)))
-      return 1;
-
-    // smallest normal value divided by 2.0
-    if (test__divsf3(0x1.0p-126F, 2.0F, UINT32_C(0x00400000)))
-      return 1;
-    // smallest subnormal result
-    if (test__divsf3(0x1.0p-126F, 0x1p+23F, UINT32_C(0x00000001)))
-      return 1;
-
-    // some misc test cases obtained by fuzzing against h/w implementation
-    if (test__divsf3(-0x1.3e75e6p-108F, -0x1.cf372p+38F, UINT32_C(0x00000006)))
-      return 1;
-    if (test__divsf3(0x1.e77c54p+81F, -0x1.e77c52p-47F, UINT32_C(0xff800000)))
-      return 1;
-    if (test__divsf3(0x1.fffffep-126F, 2.F, UINT32_C(0x00800000)))
-      return 1;
-
-    // test 1 / (1 - eps(0.5)) = 1 + eps(1)
-    if (test__divsf3(1.0F, 0x1.fffffep-1F, UINT32_C(0x3f800001)))
-      return 1;
-
-    return 0;
+int main() {
+  // Returned NaNs are assumed to be qNaN by default
+
+  // qNaN / any = qNaN
+  if (test__divsf3(makeQNaN32(), 3.F, UINT32_C(0x7fc00000)))
+    return 1;
+  // NaN / any = NaN
+  if (test__divsf3(makeNaN32(UINT32_C(0x123)), 3.F, UINT32_C(0x7fc00000)))
+    return 1;
+  // any / qNaN = qNaN
+  if (test__divsf3(3.F, makeQNaN32(), UINT32_C(0x7fc00000)))
+    return 1;
+  // any / NaN = NaN
+  if (test__divsf3(3.F, makeNaN32(UINT32_C(0x123)), UINT32_C(0x7fc00000)))
+    return 1;
+
+  // +Inf / positive = +Inf
+  if (test__divsf3(makeInf32(), 3.F, UINT32_C(0x7f800000)))
+    return 1;
+  // +Inf / negative = -Inf
+  if (test__divsf3(makeInf32(), -3.F, UINT32_C(0xff800000)))
+    return 1;
+  // -Inf / positive = -Inf
+  if (test__divsf3(makeNegativeInf32(), 3.F, UINT32_C(0xff800000)))
+    return 1;
+  // -Inf / negative = +Inf
+  if (test__divsf3(makeNegativeInf32(), -3.F, UINT32_C(0x7f800000)))
+    return 1;
+
+  // Inf / Inf = NaN
+  if (test__divsf3(makeInf32(), makeInf32(), UINT32_C(0x7fc00000)))
+    return 1;
+  // 0.0 / 0.0 = NaN
+  if (test__divsf3(+0x0.0p+0F, +0x0.0p+0F, UINT32_C(0x7fc00000)))
+    return 1;
+  // +0.0 / +Inf = +0.0
+  if (test__divsf3(+0x0.0p+0F, makeInf32(), UINT32_C(0x0)))
+    return 1;
+  // +Inf / +0.0 = +Inf
+  if (test__divsf3(makeInf32(), +0x0.0p+0F, UINT32_C(0x7f800000)))
+    return 1;
+
+  // positive / +0.0 = +Inf
+  if (test__divsf3(+1.F, +0x0.0p+0F, UINT32_C(0x7f800000)))
+    return 1;
+  // positive / -0.0 = -Inf
+  if (test__divsf3(+1.F, -0x0.0p+0F, UINT32_C(0xff800000)))
+    return 1;
+  // negative / +0.0 = -Inf
+  if (test__divsf3(-1.F, +0x0.0p+0F, UINT32_C(0xff800000)))
+    return 1;
+  // negative / -0.0 = +Inf
+  if (test__divsf3(-1.F, -0x0.0p+0F, UINT32_C(0x7f800000)))
+    return 1;
+
+  // 1/3
+  if (test__divsf3(1.F, 3.F, UINT32_C(0x3eaaaaab)))
+    return 1;
+  // smallest normal result
+  if (test__divsf3(0x1.0p-125F, 2.F, UINT32_C(0x00800000)))
+    return 1;
+
+  // divisor is exactly 1.0
+  if (test__divsf3(0x1.0p+0F, 0x1.0p+0F, UINT32_C(0x3f800000)))
+    return 1;
+  // divisor is truncated to exactly 1.0 in UQ1.15
+  if (test__divsf3(0x1.0p+0F, 0x1.0001p+0F, UINT32_C(0x3f7fff00)))
+    return 1;
+
+  // smallest normal value divided by 2.0
+  if (test__divsf3(0x1.0p-126F, 2.0F, UINT32_C(0x00400000)))
+    return 1;
+  // smallest subnormal result
+  if (test__divsf3(0x1.0p-126F, 0x1p+23F, UINT32_C(0x00000001)))
+    return 1;
+
+  // some misc test cases obtained by fuzzing against h/w implementation
+  if (test__divsf3(-0x1.3e75e6p-108F, -0x1.cf372p+38F, UINT32_C(0x00000006)))
+    return 1;
+  if (test__divsf3(0x1.e77c54p+81F, -0x1.e77c52p-47F, UINT32_C(0xff800000)))
+    return 1;
+  if (test__divsf3(0x1.fffffep-126F, 2.F, UINT32_C(0x00800000)))
+    return 1;
+
+  // test 1 / (1 - eps(0.5)) = 1 + eps(1)
+  if (test__divsf3(1.0F, 0x1.fffffep-1F, UINT32_C(0x3f800001)))
+    return 1;
+
+  return 0;
 }

[statham-arm]

I have to land this revert without CI being happy, because if nothing else, the code formatting check is never going to be happy – a side effect of the patch I'm reverting was to fix the code formatting in an existing test file!

[statham-arm]

OK, now I understand what that error message meant! The problem is that the Fuchsia buildbot is using cmake 3.22.1 (from Ubuntu 22.04), and the form of try_compile I used in my patch appeared in a later version, cmake 3.25.