[llvm] [C API] Support uinc_wrap/udec_wrap in atomicrmw when accessing the bin op (PR #87163)

[Benji Smith via llvm-commits]

https://github.com/Benjins created https://github.com/llvm/llvm-project/pull/87163

These previously were added in the C++ API in 778cf5431cafc243f81dd5c8cbd27701ff7f9120, but without updating the enum in the C API or mapping functions

Corresponding tests for all current atomicrmw bin ops have been added as well

>From cd317c8efd821217f5e9ceb37b12879241aaad4b Mon Sep 17 00:00:00 2001
From: Benji Smith <benjsith at gmail.com>
Date: Sat, 30 Mar 2024 11:57:52 -0400
Subject: [PATCH] [C API] Support uinc_wrap/udec_wrap in atomicrmw when
 accessing the bin op

These previously were added in the C++ API in 778cf5431cafc243f81dd5c8cbd27701ff7f9120,
but without updating the enum in the C API or mapping functions

Corresponding tests for all current atomicrmw bin ops have been added as well
---
 llvm/docs/ReleaseNotes.rst           |  3 +++
 llvm/include/llvm-c/Core.h           |  4 ++++
 llvm/lib/IR/Core.cpp                 |  4 ++++
 llvm/test/Bindings/llvm-c/atomics.ll | 25 +++++++++++++++++++++++++
 4 files changed, 36 insertions(+)

diff --git a/llvm/docs/ReleaseNotes.rst b/llvm/docs/ReleaseNotes.rst
index 7588048334d792..e846514b1b25fc 100644
--- a/llvm/docs/ReleaseNotes.rst
+++ b/llvm/docs/ReleaseNotes.rst
@@ -149,6 +149,9 @@ Changes to the C API
 
 * Deprecated ``LLVMConstNUWNeg`` and ``LLVMBuildNUWNeg``.
 
+* Added ``LLVMAtomicRMWBinOpUIncWrap`` and ``LLVMAtomicRMWBinOpUDecWrap`` to
+  ``LLVMAtomicRMWBinOp`` enum for AtomicRMW instructions
+
 Changes to the CodeGen infrastructure
 -------------------------------------
 
diff --git a/llvm/include/llvm-c/Core.h b/llvm/include/llvm-c/Core.h
index 254c298abe4b9c..db9322dd81bb57 100644
--- a/llvm/include/llvm-c/Core.h
+++ b/llvm/include/llvm-c/Core.h
@@ -390,6 +390,10 @@ typedef enum {
     LLVMAtomicRMWBinOpFMin, /**< Sets the value if it's smaller than the
                              original using an floating point comparison and
                              return the old one */
+    LLVMAtomicRMWBinOpUIncWrap, /**< Increments the value, wrapping back to zero
+                                 when incremented above input value */
+    LLVMAtomicRMWBinOpUDecWrap, /**< Decrements the value, wrapping back to
+                                 the input value when decremented below zero */
 } LLVMAtomicRMWBinOp;
 
 typedef enum {
diff --git a/llvm/lib/IR/Core.cpp b/llvm/lib/IR/Core.cpp
index 3aee6195725253..9d72e9c4df4580 100644
--- a/llvm/lib/IR/Core.cpp
+++ b/llvm/lib/IR/Core.cpp
@@ -3755,6 +3755,8 @@ static AtomicRMWInst::BinOp mapFromLLVMRMWBinOp(LLVMAtomicRMWBinOp BinOp) {
     case LLVMAtomicRMWBinOpFSub: return AtomicRMWInst::FSub;
     case LLVMAtomicRMWBinOpFMax: return AtomicRMWInst::FMax;
     case LLVMAtomicRMWBinOpFMin: return AtomicRMWInst::FMin;
+    case LLVMAtomicRMWBinOpUIncWrap: return AtomicRMWInst::UIncWrap;
+    case LLVMAtomicRMWBinOpUDecWrap: return AtomicRMWInst::UDecWrap;
   }
 
   llvm_unreachable("Invalid LLVMAtomicRMWBinOp value!");
@@ -3777,6 +3779,8 @@ static LLVMAtomicRMWBinOp mapToLLVMRMWBinOp(AtomicRMWInst::BinOp BinOp) {
     case AtomicRMWInst::FSub: return LLVMAtomicRMWBinOpFSub;
     case AtomicRMWInst::FMax: return LLVMAtomicRMWBinOpFMax;
     case AtomicRMWInst::FMin: return LLVMAtomicRMWBinOpFMin;
+    case AtomicRMWInst::UIncWrap: return LLVMAtomicRMWBinOpUIncWrap;
+    case AtomicRMWInst::UDecWrap: return LLVMAtomicRMWBinOpUDecWrap;
     default: break;
   }
 
diff --git a/llvm/test/Bindings/llvm-c/atomics.ll b/llvm/test/Bindings/llvm-c/atomics.ll
index e64a29944ef9df..162368c9d98d0e 100644
--- a/llvm/test/Bindings/llvm-c/atomics.ll
+++ b/llvm/test/Bindings/llvm-c/atomics.ll
@@ -36,6 +36,31 @@ define void @atomic_load_store(ptr %word) {
   ret void
 }
 
+define void @atomic_rmw_ops(ptr %p, i32 %i, float %f) {
+  ; Test all atomicrmw operations
+  %a.xchg      = atomicrmw xchg      ptr %p, i32 %i acq_rel, align 8
+  %a.add       = atomicrmw add       ptr %p, i32 %i acq_rel, align 8
+  %a.sub       = atomicrmw sub       ptr %p, i32 %i acq_rel, align 8
+  %a.and       = atomicrmw and       ptr %p, i32 %i acq_rel, align 8
+  %a.nand      = atomicrmw nand      ptr %p, i32 %i acq_rel, align 8
+  %a.or        = atomicrmw or        ptr %p, i32 %i acq_rel, align 8
+  %a.xor       = atomicrmw xor       ptr %p, i32 %i acq_rel, align 8
+  %a.max       = atomicrmw max       ptr %p, i32 %i acq_rel, align 8
+  %a.min       = atomicrmw min       ptr %p, i32 %i acq_rel, align 8
+  %a.umax      = atomicrmw umax      ptr %p, i32 %i acq_rel, align 8
+  %a.umin      = atomicrmw umin      ptr %p, i32 %i acq_rel, align 8
+
+  %a.fadd      = atomicrmw fadd      ptr %p, float %f acq_rel, align 8
+  %a.fsub      = atomicrmw fsub      ptr %p, float %f acq_rel, align 8
+  %a.fmax      = atomicrmw fmax      ptr %p, float %f acq_rel, align 8
+  %a.fmin      = atomicrmw fmin      ptr %p, float %f acq_rel, align 8
+
+  %a.uinc_wrap = atomicrmw uinc_wrap ptr %p, i32 %i acq_rel, align 8
+  %a.udec_wrap = atomicrmw udec_wrap ptr %p, i32 %i acq_rel, align 8
+
+  ret void
+}
+
 define i32 @main() {
   %1 = alloca i32, align 4
   %2 = cmpxchg ptr %1, i32 2, i32 3 seq_cst acquire