[C API] Add support for setting/getting new nneg flag on zext instructions (#73592)

This flag was added in #67982, but was not yet accessible via the C API.
This commit adds a getter/setter for this flag, and a test for it.

Author: Benjins

llvm/docs/ReleaseNotes.rst

@@ -199,6 +199,9 @@ Changes to the C API
   The option structure exposes an additional setting (i.e., the target ABI) and
   provides default values for unspecified settings.
 
+* Added ``LLVMGetNNeg`` and ``LLVMSetNNeg`` for setting/getting the new nneg flag
+  on zext instructions
+
 Changes to the CodeGen infrastructure
 -------------------------------------
 

llvm/include/llvm-c/Core.h

@@ -3974,6 +3974,17 @@ void LLVMSetNSW(LLVMValueRef ArithInst, LLVMBool HasNSW);
 LLVMBool LLVMGetExact(LLVMValueRef DivOrShrInst);
 void LLVMSetExact(LLVMValueRef DivOrShrInst, LLVMBool IsExact);
 
+/**
+ * Gets if the instruction has the non-negative flag set
+ * Only valid for zext instructions
+ */
+LLVMBool LLVMGetNNeg(LLVMValueRef NonNegInst);
+/**
+ * Sets the non-negative flag for the instruction
+ * Only valid for zext instructions
+ */
+void LLVMSetNNeg(LLVMValueRef NonNegInst, LLVMBool IsNonNeg);
+
 /* Memory */
 LLVMValueRef LLVMBuildMalloc(LLVMBuilderRef, LLVMTypeRef Ty, const char *Name);
 LLVMValueRef LLVMBuildArrayMalloc(LLVMBuilderRef, LLVMTypeRef Ty,

llvm/lib/IR/Core.cpp

@@ -3454,6 +3454,16 @@ void LLVMSetExact(LLVMValueRef DivOrShrInst, LLVMBool IsExact) {
   cast<Instruction>(P)->setIsExact(IsExact);
 }
 
+LLVMBool LLVMGetNNeg(LLVMValueRef NonNegInst) {
+  Value *P = unwrap<Value>(NonNegInst);
+  return cast<Instruction>(P)->hasNonNeg();
+}
+
+void LLVMSetNNeg(LLVMValueRef NonNegInst, LLVMBool IsNonNeg) {
+  Value *P = unwrap<Value>(NonNegInst);
+  cast<Instruction>(P)->setNonNeg(IsNonNeg);
+}
+
 /*--.. Memory ..............................................................--*/
 
 LLVMValueRef LLVMBuildMalloc(LLVMBuilderRef B, LLVMTypeRef Ty,

llvm/test/Bindings/llvm-c/echo.ll

@@ -90,6 +90,8 @@ define i32 @iops(i32 %a, i32 %b) {
   %21 = sdiv exact i32 %20, %2
   %22 = lshr exact i32 %21, %4
   %23 = ashr exact i32 %22, %14
+  %24 = zext i32 %23 to i64
+  %25 = zext nneg i32 %23 to i64
   ret i32 %23
 }
 

llvm/tools/llvm-c-test/echo.cpp

@@ -899,6 +899,14 @@ struct FunCloner {
         Dst = LLVMBuildFence(Builder, Ordering, IsSingleThreaded, Name);
         break;
       }
+      case LLVMZExt: {
+        LLVMValueRef Val = CloneValue(LLVMGetOperand(Src, 0));
+        LLVMTypeRef DestTy = CloneType(LLVMTypeOf(Src));
+        LLVMBool NNeg = LLVMGetNNeg(Src);
+        Dst = LLVMBuildZExt(Builder, Val, DestTy, Name);
+        LLVMSetNNeg(Dst, NNeg);
+        break;
+      }
       default:
         break;
     }