[llvm-branch-commits] [llvm] X86: Make sure compiler-rt div calls are not added for msvc (PR #164591)

[Matt Arsenault via llvm-branch-commits]

https://github.com/arsenm created https://github.com/llvm/llvm-project/pull/164591

The current predicate system is primitive, we ought to have
a way to list a chain of alternatives.

>From c9b25df5c291552d42ef1e3de0d7cf8d3e077eab Mon Sep 17 00:00:00 2001
From: Matt Arsenault <Matthew.Arsenault at amd.com>
Date: Wed, 22 Oct 2025 16:30:46 +0900
Subject: [PATCH] X86: Make sure compiler-rt div calls are not added for msvc

The current predicate system is primitive, we ought to have
a way to list a chain of alternatives.
---
 llvm/include/llvm/IR/RuntimeLibcalls.td | 14 ++++++++++++--
 1 file changed, 12 insertions(+), 2 deletions(-)

diff --git a/llvm/include/llvm/IR/RuntimeLibcalls.td b/llvm/include/llvm/IR/RuntimeLibcalls.td
index 243b864ccf033..c9e08e844f2a0 100644
--- a/llvm/include/llvm/IR/RuntimeLibcalls.td
+++ b/llvm/include/llvm/IR/RuntimeLibcalls.td
@@ -2450,6 +2450,11 @@ def _aullrem : RuntimeLibcallImpl<UREM_I64>;
 def _allmul : RuntimeLibcallImpl<MUL_I64>;
 }
 
+// FIXME: Should have utility function to filter by known provider.
+defvar WindowsDivRemMulLibcallOverrides = [
+  __divdi3, __udivdi3, __moddi3, __umoddi3, __muldi3
+];
+
 //===----------------------------------------------------------------------===//
 // X86 Runtime Libcalls
 //===----------------------------------------------------------------------===//
@@ -2471,7 +2476,7 @@ defvar X86_F128_Libcalls = LibcallImpls<(add LibmF128Libcalls, LibmF128FiniteLib
 defvar SinCosF32F64Libcalls = LibcallImpls<(add sincosf, sincos), hasSinCos_f32_f64>;
 
 defvar X86CommonLibcalls =
-  (add WinDefaultLibcallImpls,
+  (add (sub WinDefaultLibcallImpls, WindowsDivRemMulLibcallOverrides),
        DarwinSinCosStret, DarwinExp10,
        X86_F128_Libcalls,
        LibmHasSinCosF80, // FIXME: Depends on long double
@@ -2494,10 +2499,15 @@ defvar Windows32DivRemMulCalls =
   LibcallsWithCC<(add WindowsDivRemMulLibcalls), X86_STDCALL,
   RuntimeLibcallPredicate<"TT.isWindowsMSVCEnvironment() || TT.isWindowsItaniumEnvironment()">>;
 
+defvar NotWindows32DivRemMulCalls =
+  LibcallImpls<(add WindowsDivRemMulLibcallOverrides),
+    RuntimeLibcallPredicate<"!TT.isWindowsMSVCEnvironment() && !TT.isWindowsItaniumEnvironment()">>;
+
 def X86_32SystemLibrary
     : SystemRuntimeLibrary<isX86_32,
       (add X86CommonLibcalls,
-           Windows32DivRemMulCalls)>;
+             NotWindows32DivRemMulCalls,
+             Windows32DivRemMulCalls)>;
 
 def X86_64SystemLibrary
     : SystemRuntimeLibrary<isX86_64,