RuntimeLibcalls: Use array initializers for default values

[arsenm]

No description provided.

[arsenm]

• RuntimeLibcalls: Use array initializers for default values #143082 👈 (View in Graphite)
• RuntimeLibcalls: Cleanup sincos predicate functions #143081
• DAG: Move soft float predicate management into RuntimeLibcalls #142905 : 1 other dependent PR (#142912 )
• DAG: Assert fcmp uno runtime calls are boolean values #142898
• main

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[llvmbot]

@llvm/pr-subscribers-llvm-ir

Author: Matt Arsenault (arsenm)

Changes

---

Full diff: https://github.com/llvm/llvm-project/pull/143082.diff

2 Files Affected:

• (modified) llvm/include/llvm/IR/RuntimeLibcalls.h (+5-3)
• (modified) llvm/lib/IR/RuntimeLibcalls.cpp (-10)

diff --git a/llvm/include/llvm/IR/RuntimeLibcalls.h b/llvm/include/llvm/IR/RuntimeLibcalls.h
index d2704d5aa2616..d67430968edf1 100644
--- a/llvm/include/llvm/IR/RuntimeLibcalls.h
+++ b/llvm/include/llvm/IR/RuntimeLibcalls.h
@@ -90,10 +90,11 @@ struct RuntimeLibcallsInfo {
 
 private:
   /// Stores the name each libcall.
-  const char *LibcallRoutineNames[RTLIB::UNKNOWN_LIBCALL + 1];
+  const char *LibcallRoutineNames[RTLIB::UNKNOWN_LIBCALL + 1] = {nullptr};
 
   /// Stores the CallingConv that should be used for each libcall.
-  CallingConv::ID LibcallCallingConvs[RTLIB::UNKNOWN_LIBCALL];
+  CallingConv::ID LibcallCallingConvs[RTLIB::UNKNOWN_LIBCALL] = {
+      CallingConv::C};
 
   /// The condition type that should be used to test the result of each of the
   /// soft floating-point comparison libcall against integer zero.
@@ -101,7 +102,8 @@ struct RuntimeLibcallsInfo {
   // FIXME: This is only relevant for the handful of floating-point comparison
   // runtime calls; it's excessive to have a table entry for every single
   // opcode.
-  CmpInst::Predicate SoftFloatCompareLibcallPredicates[RTLIB::UNKNOWN_LIBCALL];
+  CmpInst::Predicate SoftFloatCompareLibcallPredicates[RTLIB::UNKNOWN_LIBCALL] =
+      {CmpInst::BAD_ICMP_PREDICATE};
 
   static bool darwinHasSinCosStret(const Triple &TT) {
     assert(TT.isOSDarwin() && "should be called with darwin triple");
diff --git a/llvm/lib/IR/RuntimeLibcalls.cpp b/llvm/lib/IR/RuntimeLibcalls.cpp
index a6fda0cfeadd2..01978b7ae39e3 100644
--- a/llvm/lib/IR/RuntimeLibcalls.cpp
+++ b/llvm/lib/IR/RuntimeLibcalls.cpp
@@ -12,9 +12,6 @@ using namespace llvm;
 using namespace RTLIB;
 
 void RuntimeLibcallsInfo::initSoftFloatCmpLibcallPredicates() {
-  std::fill(SoftFloatCompareLibcallPredicates,
-            SoftFloatCompareLibcallPredicates + RTLIB::UNKNOWN_LIBCALL,
-            CmpInst::BAD_ICMP_PREDICATE);
   SoftFloatCompareLibcallPredicates[RTLIB::OEQ_F32] = CmpInst::ICMP_EQ;
   SoftFloatCompareLibcallPredicates[RTLIB::OEQ_F64] = CmpInst::ICMP_EQ;
   SoftFloatCompareLibcallPredicates[RTLIB::OEQ_F128] = CmpInst::ICMP_EQ;
@@ -48,19 +45,12 @@ void RuntimeLibcallsInfo::initSoftFloatCmpLibcallPredicates() {
 /// Set default libcall names. If a target wants to opt-out of a libcall it
 /// should be placed here.
 void RuntimeLibcallsInfo::initLibcalls(const Triple &TT) {
-  std::fill(std::begin(LibcallRoutineNames), std::end(LibcallRoutineNames),
-            nullptr);
-
   initSoftFloatCmpLibcallPredicates();
 
 #define HANDLE_LIBCALL(code, name) setLibcallName(RTLIB::code, name);
 #include "llvm/IR/RuntimeLibcalls.def"
 #undef HANDLE_LIBCALL
 
-  // Initialize calling conventions to their default.
-  for (int LC = 0; LC < RTLIB::UNKNOWN_LIBCALL; ++LC)
-    setLibcallCallingConv((RTLIB::Libcall)LC, CallingConv::C);
-
   // Use the f128 variants of math functions on x86
   if (TT.isX86() && TT.isGNUEnvironment()) {
     setLibcallName(RTLIB::REM_F128, "fmodf128");

[DanielKristofKiss]

CmpInst::BAD_ICMP_PREDICATE is not zero (42) so only the first element of the array will be initialized to CmpInst::BAD_ICMP_PREDICATE rest will be zero.

[arsenm]

There's no actual reason to initialize this, the only fields that are used are explicitly initialized separately. We should shrink the array as the FIXME says

[efriedma-quic]

Explicitly writing "CallingConv::C" here is confusing; either just use {}, or use something like SmallVector that actually has a constructor which fills an arbitrary value.

[efriedma-quic]

LGTM

[arsenm]

Merge activity

• Jun 17, 12:37 AM UTC: A user started a stack merge that includes this pull request via Graphite.
• Jun 17, 12:46 AM UTC: Graphite couldn't merge this PR because it had conflicts with the trunk branch.
• Jun 17, 12:58 AM UTC: A user started a stack merge that includes this pull request via Graphite.
• Jun 17, 1:00 AM UTC: @arsenm merged this pull request with Graphite.