[C API] Add getter/setter for samesign flag on icmp (#145247)

This was added to the C++ API in
https://github.com/llvm/llvm-project/pull/111419 so this change adds
accessors in the C API, along with a couple tests.

llvm/docs/ReleaseNotes.md

@@ -251,6 +251,9 @@ Changes to the C API
 * Added ``LLVMDIBuilderCreateEnumeratorOfArbitraryPrecision`` for creating
   debugging metadata of enumerators larger than 64 bits.
 
+* Added ``LLVMGetICmpSameSign`` and ``LLVMSetICmpSameSign`` for the `samesign`
+  flag on `icmp` instructions.
+
 Changes to the CodeGen infrastructure
 -------------------------------------
 

llvm/include/llvm-c/Core.h

@@ -3675,6 +3675,24 @@ LLVMOpcode LLVMGetInstructionOpcode(LLVMValueRef Inst);
  */
 LLVMIntPredicate LLVMGetICmpPredicate(LLVMValueRef Inst);
 
+/**
+ * Get whether or not an icmp instruction has the samesign flag.
+ *
+ * This is only valid for instructions that correspond to llvm::ICmpInst.
+ *
+ * @see llvm::ICmpInst::hasSameSign()
+ */
+LLVMBool LLVMGetICmpSameSign(LLVMValueRef Inst);
+
+/**
+ * Set the samesign flag on an icmp instruction.
+ *
+ * This is only valid for instructions that correspond to llvm::ICmpInst.
+ *
+ * @see llvm::ICmpInst::setSameSign()
+ */
+void LLVMSetICmpSameSign(LLVMValueRef Inst, LLVMBool SameSign);
+
 /**
  * Obtain the float predicate of an instruction.
  *

llvm/lib/IR/Core.cpp

@@ -2951,6 +2951,14 @@ LLVMIntPredicate LLVMGetICmpPredicate(LLVMValueRef Inst) {
   return (LLVMIntPredicate)0;
 }
 
+LLVMBool LLVMGetICmpSameSign(LLVMValueRef Inst) {
+  return unwrap<ICmpInst>(Inst)->hasSameSign();
+}
+
+void LLVMSetICmpSameSign(LLVMValueRef Inst, LLVMBool SameSign) {
+  unwrap<ICmpInst>(Inst)->setSameSign(SameSign);
+}
+
 LLVMRealPredicate LLVMGetFCmpPredicate(LLVMValueRef Inst) {
   if (FCmpInst *I = dyn_cast<FCmpInst>(unwrap(Inst)))
     return (LLVMRealPredicate)I->getPredicate();

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

@@ -417,6 +417,14 @@ define ptr @test_gep_no_wrap_flags(ptr %0) {
   ret ptr %gep.nusw
 }
 
+define void @test_icmp_same_sign(i32 %a, i32 %b) {
+  %icmp.1 = icmp eq i32 %a, %b
+  %icmp.2 = icmp slt i32 %a, %b
+  %icmp.3 = icmp samesign eq i32 %a, %b
+  %icmp.4 = icmp samesign slt i32 %a, %b
+  ret void
+}
+
 !llvm.dbg.cu = !{!0, !2}
 !llvm.module.flags = !{!3}
 

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

@@ -823,9 +823,11 @@ struct FunCloner {
       }
       case LLVMICmp: {
         LLVMIntPredicate Pred = LLVMGetICmpPredicate(Src);
+        LLVMBool IsSameSign = LLVMGetICmpSameSign(Src);
         LLVMValueRef LHS = CloneValue(LLVMGetOperand(Src, 0));
         LLVMValueRef RHS = CloneValue(LLVMGetOperand(Src, 1));
         Dst = LLVMBuildICmp(Builder, Pred, LHS, RHS, Name);
+        LLVMSetICmpSameSign(Dst, IsSameSign);
         break;
       }
       case LLVMPHI: {