[PATCH] D137711: [X86] Use lock add/sub for cases that we only care about the EFLAGS

[Simon Pilgrim via Phabricator via llvm-commits]

RKSimon added inline comments.


================
Comment at: llvm/lib/Target/X86/X86ISelLowering.cpp:31340
+      return Pred == CmpInst::ICMP_EQ;
+    if (match(I, m_c_Add(m_Specific(Op), m_Value())) && I->hasOneUse() &&
+        match(I->user_back(), m_ICmp(Pred, m_Value(), m_ZeroInt())))
----------------
m_OneUse(m_c_Add(...)) ?


================
Comment at: llvm/lib/Target/X86/X86ISelLowering.cpp:31348
+      return Pred == CmpInst::ICMP_EQ;
+    if (match(I, m_Sub(m_Value(), m_Specific(Op))) && I->hasOneUse() &&
+        match(I->user_back(), m_ICmp(Pred, m_Value(), m_ZeroInt())))
----------------
m_OneUse(m_Sub(...))?


================
Comment at: llvm/lib/Target/X86/X86ISelLowering.cpp:31368
+  X86::CondCode CC =
+      ICI->getPredicate() == CmpInst::ICMP_EQ ? X86::COND_E : X86::COND_S;
+  Intrinsic::ID IID = Intrinsic::not_intrinsic;
----------------
assert ICI->getPredicate() for EQ/SLT ?


================
Comment at: llvm/test/CodeGen/X86/pr58685.ll:4
+
+define dso_local noundef zeroext i1 @_Z13lock_add_seteRSt6atomicIjEj(ptr nocapture noundef nonnull align 4 dereferenceable(4) %0, i32 noundef %1) local_unnamed_addr #0 {
+; CHECK-LABEL: _Z13lock_add_seteRSt6atomicIjEj:
----------------
Cleanup the method names and drop the dso_local / atttributes etc?


Repository:
  rG LLVM Github Monorepo

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  https://reviews.llvm.org/D137711/new/

https://reviews.llvm.org/D137711