[llvm] [NFC][TLI] Move VecFuncs to statics to reduce stack usage (PR #86829)

[Alex MacLean via llvm-commits]

https://github.com/AlexMaclean created https://github.com/llvm/llvm-project/pull/86829

`TargetLibraryInfoImpl::addVectorizableFunctionsFromVecLib` has a lot of data in local stack arrays, which MSVC keeps on the stack even in release builds. To reduce stack usage, the data arrays (which are const), are moved outside the function as statics. This drops the method stack usage to be negligible.

>From edf0e1237ccb38b80f465277cba4886b1e8e38dd Mon Sep 17 00:00:00 2001
From: Alex MacLean <amaclean at nvidia.com>
Date: Mon, 25 Mar 2024 22:43:51 +0000
Subject: [PATCH] [NFC][TLI] Move VecFuncs to statics to reduce stack usage

---
 llvm/lib/Analysis/TargetLibraryInfo.cpp | 130 +++++++++++++-----------
 1 file changed, 68 insertions(+), 62 deletions(-)

diff --git a/llvm/lib/Analysis/TargetLibraryInfo.cpp b/llvm/lib/Analysis/TargetLibraryInfo.cpp
index c8195584ade378..9e17dcaa55925d 100644
--- a/llvm/lib/Analysis/TargetLibraryInfo.cpp
+++ b/llvm/lib/Analysis/TargetLibraryInfo.cpp
@@ -1190,107 +1190,113 @@ void TargetLibraryInfoImpl::addVectorizableFunctions(ArrayRef<VecDesc> Fns) {
   llvm::sort(ScalarDescs, compareByVectorFnName);
 }
 
+static const VecDesc VecFuncs_Accelerate[] = {
+#define TLI_DEFINE_ACCELERATE_VECFUNCS
+#include "llvm/Analysis/VecFuncs.def"
+};
+
+static const VecDesc VecFuncs_DarwinLibSystemM[] = {
+#define TLI_DEFINE_DARWIN_LIBSYSTEM_M_VECFUNCS
+#include "llvm/Analysis/VecFuncs.def"
+};
+
+static const VecDesc VecFuncs_LIBMVEC_X86[] = {
+#define TLI_DEFINE_LIBMVEC_X86_VECFUNCS
+#include "llvm/Analysis/VecFuncs.def"
+};
+
+static const VecDesc VecFuncs_MASSV[] = {
+#define TLI_DEFINE_MASSV_VECFUNCS
+#include "llvm/Analysis/VecFuncs.def"
+};
+
+static const VecDesc VecFuncs_SVML[] = {
+#define TLI_DEFINE_SVML_VECFUNCS
+#include "llvm/Analysis/VecFuncs.def"
+};
+
+static const VecDesc VecFuncs_SLEEFGNUABI_VF2[] = {
+#define TLI_DEFINE_SLEEFGNUABI_VF2_VECFUNCS
+#define TLI_DEFINE_VECFUNC(SCAL, VEC, VF, VABI_PREFIX)                         \
+  {SCAL, VEC, VF, /* MASK = */ false, VABI_PREFIX},
+#include "llvm/Analysis/VecFuncs.def"
+};
+static const VecDesc VecFuncs_SLEEFGNUABI_VF4[] = {
+#define TLI_DEFINE_SLEEFGNUABI_VF4_VECFUNCS
+#define TLI_DEFINE_VECFUNC(SCAL, VEC, VF, VABI_PREFIX)                         \
+  {SCAL, VEC, VF, /* MASK = */ false, VABI_PREFIX},
+#include "llvm/Analysis/VecFuncs.def"
+};
+static const VecDesc VecFuncs_SLEEFGNUABI_VFScalable[] = {
+#define TLI_DEFINE_SLEEFGNUABI_SCALABLE_VECFUNCS
+#define TLI_DEFINE_VECFUNC(SCAL, VEC, VF, MASK, VABI_PREFIX)                   \
+  {SCAL, VEC, VF, MASK, VABI_PREFIX},
+#include "llvm/Analysis/VecFuncs.def"
+};
+
+static const VecDesc VecFuncs_ArmPL[] = {
+#define TLI_DEFINE_ARMPL_VECFUNCS
+#define TLI_DEFINE_VECFUNC(SCAL, VEC, VF, MASK, VABI_PREFIX)                   \
+  {SCAL, VEC, VF, MASK, VABI_PREFIX},
+#include "llvm/Analysis/VecFuncs.def"
+};
+
+const VecDesc VecFuncs_AMDLIBM[] = {
+#define TLI_DEFINE_AMDLIBM_VECFUNCS
+#define TLI_DEFINE_VECFUNC(SCAL, VEC, VF, MASK, VABI_PREFIX)                   \
+  {SCAL, VEC, VF, MASK, VABI_PREFIX},
+#include "llvm/Analysis/VecFuncs.def"
+};
+
 void TargetLibraryInfoImpl::addVectorizableFunctionsFromVecLib(
     enum VectorLibrary VecLib, const llvm::Triple &TargetTriple) {
   switch (VecLib) {
   case Accelerate: {
-    const VecDesc VecFuncs[] = {
-    #define TLI_DEFINE_ACCELERATE_VECFUNCS
-    #include "llvm/Analysis/VecFuncs.def"
-    };
-    addVectorizableFunctions(VecFuncs);
+    addVectorizableFunctions(VecFuncs_Accelerate);
     break;
   }
   case DarwinLibSystemM: {
-    const VecDesc VecFuncs[] = {
-    #define TLI_DEFINE_DARWIN_LIBSYSTEM_M_VECFUNCS
-    #include "llvm/Analysis/VecFuncs.def"
-    };
-    addVectorizableFunctions(VecFuncs);
+    addVectorizableFunctions(VecFuncs_DarwinLibSystemM);
     break;
   }
   case LIBMVEC_X86: {
-    const VecDesc VecFuncs[] = {
-    #define TLI_DEFINE_LIBMVEC_X86_VECFUNCS
-    #include "llvm/Analysis/VecFuncs.def"
-    };
-    addVectorizableFunctions(VecFuncs);
+    addVectorizableFunctions(VecFuncs_LIBMVEC_X86);
     break;
   }
   case MASSV: {
-    const VecDesc VecFuncs[] = {
-    #define TLI_DEFINE_MASSV_VECFUNCS
-    #include "llvm/Analysis/VecFuncs.def"
-    };
-    addVectorizableFunctions(VecFuncs);
+    addVectorizableFunctions(VecFuncs_MASSV);
     break;
   }
   case SVML: {
-    const VecDesc VecFuncs[] = {
-    #define TLI_DEFINE_SVML_VECFUNCS
-    #include "llvm/Analysis/VecFuncs.def"
-    };
-    addVectorizableFunctions(VecFuncs);
+    addVectorizableFunctions(VecFuncs_SVML);
     break;
   }
   case SLEEFGNUABI: {
-    const VecDesc VecFuncs_VF2[] = {
-#define TLI_DEFINE_SLEEFGNUABI_VF2_VECFUNCS
-#define TLI_DEFINE_VECFUNC(SCAL, VEC, VF, VABI_PREFIX)                         \
-  {SCAL, VEC, VF, /* MASK = */ false, VABI_PREFIX},
-#include "llvm/Analysis/VecFuncs.def"
-    };
-    const VecDesc VecFuncs_VF4[] = {
-#define TLI_DEFINE_SLEEFGNUABI_VF4_VECFUNCS
-#define TLI_DEFINE_VECFUNC(SCAL, VEC, VF, VABI_PREFIX)                         \
-  {SCAL, VEC, VF, /* MASK = */ false, VABI_PREFIX},
-#include "llvm/Analysis/VecFuncs.def"
-    };
-    const VecDesc VecFuncs_VFScalable[] = {
-#define TLI_DEFINE_SLEEFGNUABI_SCALABLE_VECFUNCS
-#define TLI_DEFINE_VECFUNC(SCAL, VEC, VF, MASK, VABI_PREFIX)                   \
-  {SCAL, VEC, VF, MASK, VABI_PREFIX},
-#include "llvm/Analysis/VecFuncs.def"
-    };
-
     switch (TargetTriple.getArch()) {
     default:
       break;
     case llvm::Triple::aarch64:
     case llvm::Triple::aarch64_be:
-      addVectorizableFunctions(VecFuncs_VF2);
-      addVectorizableFunctions(VecFuncs_VF4);
-      addVectorizableFunctions(VecFuncs_VFScalable);
+      addVectorizableFunctions(VecFuncs_SLEEFGNUABI_VF2);
+      addVectorizableFunctions(VecFuncs_SLEEFGNUABI_VF4);
+      addVectorizableFunctions(VecFuncs_SLEEFGNUABI_VFScalable);
       break;
     }
     break;
   }
   case ArmPL: {
-    const VecDesc VecFuncs[] = {
-#define TLI_DEFINE_ARMPL_VECFUNCS
-#define TLI_DEFINE_VECFUNC(SCAL, VEC, VF, MASK, VABI_PREFIX)                   \
-  {SCAL, VEC, VF, MASK, VABI_PREFIX},
-#include "llvm/Analysis/VecFuncs.def"
-    };
-
     switch (TargetTriple.getArch()) {
     default:
       break;
     case llvm::Triple::aarch64:
     case llvm::Triple::aarch64_be:
-      addVectorizableFunctions(VecFuncs);
+      addVectorizableFunctions(VecFuncs_ArmPL);
       break;
     }
     break;
   }
   case AMDLIBM: {
-    const VecDesc VecFuncs[] = {
-#define TLI_DEFINE_AMDLIBM_VECFUNCS
-#define TLI_DEFINE_VECFUNC(SCAL, VEC, VF, MASK, VABI_PREFIX)                   \
-  {SCAL, VEC, VF, MASK, VABI_PREFIX},
-#include "llvm/Analysis/VecFuncs.def"
-    };
-    addVectorizableFunctions(VecFuncs);
+    addVectorizableFunctions(VecFuncs_AMDLIBM);
     break;
   }
   case NoLibrary: