[llvm-branch-commits] [compiler-rt] [compiler-rt][ARM] Optimized single-precision FP comparisons (PR #179925)

[Saleem Abdulrasool via llvm-branch-commits]

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@@ -0,0 +1,55 @@
+//===-- cmpsf2.S - single-precision floating point comparison -------------===//
+//
+// 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 function has the semantics of GNU __cmpsf2: it's a three-way compare
+// which returns <0 if x<y, 0 if x==y, and >0 if x>y. If the result is
+// unordered (i.e. x or y or both is NaN) then it returns >0.
+//
+// This also makes it suitable for use as all of __eqsf2, __nesf2, __ltsf2 or
+// __lesf2.
+//
+//===----------------------------------------------------------------------===//
+
+#include "../../assembly.h"
+
+  .syntax unified
+  .text
+  .p2align 2
+
+op0 .req r0
+op1 .req r1
+.macro SetReturnRegister
+  bhi 0f
+  blo 1f
+  movs r0, #0
+  bx lr
+0:
+  movs r0, #1
+  bx lr
+1:
+  movs r0, #1
+  rsbs r0, r0, #0
+  bx lr
+.endm
+
+DEFINE_COMPILERRT_FUNCTION_ALIAS(__cmpsf2, __compiler_rt_softfp_cmpsf2)
+DEFINE_COMPILERRT_FUNCTION_ALIAS(__lesf2, __cmpsf2)
+DEFINE_COMPILERRT_FUNCTION_ALIAS(__ltsf2, __cmpsf2)
+DEFINE_COMPILERRT_FUNCTION_ALIAS(__eqsf2, __cmpsf2)
+DEFINE_COMPILERRT_FUNCTION_ALIAS(__nesf2, __cmpsf2)
+
+DEFINE_COMPILERRT_THUMB_FUNCTION(__compiler_rt_softfp_cmpsf2)
+  #include "fcmp.h"
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compnerd wrote:

Might be worth leaving the context in a comment.

https://github.com/llvm/llvm-project/pull/179925