Reapply "Add support for #pragma float_control" with improvements to

test cases
Add support for #pragma float_control

Reviewers: rjmccall, erichkeane, sepavloff

Differential Revision: https://reviews.llvm.org/D72841

This reverts commit 85dc033caccaa6ab919d57f9759290be41240146, and makes
corrections to the test cases that failed on buildbots.

1 files changed, 47 insertions, 0 deletions

diff --git a/clang/test/CodeGen/fp-floatcontrol-pragma.cpp b/clang/test/CodeGen/fp-floatcontrol-pragma.cpp
new file mode 100644
index 000000000000..caaab3ca4f84
--- /dev/null
+++ b/clang/test/CodeGen/fp-floatcontrol-pragma.cpp
@@ -0,0 +1,47 @@
+// RUN: %clang_cc1 -triple x86_64-linux-gnu -emit-llvm -o - %s | FileCheck %s
+
+float fff(float x, float y) {
+// CHECK-LABEL: define float @_Z3fffff{{.*}}
+// CHECK: entry
+#pragma float_control(except, on)
+  float z;
+  z = z * z;
+  //CHECK: llvm.experimental.constrained.fmul{{.*}}
+  {
+    z = x * y;
+    //CHECK: llvm.experimental.constrained.fmul{{.*}}
+  }
+  {
+// This pragma has no effect since if there are any fp intrin in the
+// function then all the operations need to be fp intrin
+#pragma float_control(except, off)
+    z = z + x * y;
+    //CHECK: llvm.experimental.constrained.fmul{{.*}}
+  }
+  z = z * z;
+  //CHECK: llvm.experimental.constrained.fmul{{.*}}
+  return z;
+}
+float check_precise(float x, float y) {
+  // CHECK-LABEL: define float @_Z13check_preciseff{{.*}}
+  float z;
+  {
+#pragma float_control(precise, on)
+    z = x * y + z;
+    //CHECK: llvm.fmuladd{{.*}}
+  }
+  {
+#pragma float_control(precise, off)
+    z = x * y + z;
+    //CHECK: fmul fast float
+    //CHECK: fadd fast float
+  }
+  return z;
+}
+float fma_test1(float a, float b, float c) {
+// CHECK-LABEL define float @_Z9fma_test1fff{{.*}}
+#pragma float_control(precise, on)
+  float x = a * b + c;
+  //CHECK: fmuladd
+  return x;
+}