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

[Benjins]

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

[llvmbot]

@llvm/pr-subscribers-llvm-ir

Author: Benji Smith (Benjins)

Changes

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

---

Full diff: https://github.com/llvm/llvm-project/pull/73592.diff

5 Files Affected:

• (modified) llvm/docs/ReleaseNotes.rst (+3)
• (modified) llvm/include/llvm-c/Core.h (+11)
• (modified) llvm/lib/IR/Core.cpp (+10)
• (modified) llvm/test/Bindings/llvm-c/echo.ll (+2)
• (modified) llvm/tools/llvm-c-test/echo.cpp (+8)

diff --git a/llvm/docs/ReleaseNotes.rst b/llvm/docs/ReleaseNotes.rst
index 2c663932f8f8c2f..2c160f1707cbb95 100644
--- a/llvm/docs/ReleaseNotes.rst
+++ b/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
 -------------------------------------
 
diff --git a/llvm/include/llvm-c/Core.h b/llvm/include/llvm-c/Core.h
index b752fd42a7a12cf..b16f67ef02f3362 100644
--- a/llvm/include/llvm-c/Core.h
+++ b/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,
diff --git a/llvm/lib/IR/Core.cpp b/llvm/lib/IR/Core.cpp
index b089dd48e55b4d4..e07664f8a17c6d9 100644
--- a/llvm/lib/IR/Core.cpp
+++ b/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,
diff --git a/llvm/test/Bindings/llvm-c/echo.ll b/llvm/test/Bindings/llvm-c/echo.ll
index 5daa238bfb8e533..72d5b455badcbec 100644
--- a/llvm/test/Bindings/llvm-c/echo.ll
+++ b/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
 }
 
diff --git a/llvm/tools/llvm-c-test/echo.cpp b/llvm/tools/llvm-c-test/echo.cpp
index 06966ce528eae4d..3b07ccb29f3e061 100644
--- a/llvm/tools/llvm-c-test/echo.cpp
+++ b/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;
     }

[nikic]

LGTM

[Benjins]

Not sure what the issue with the build is: the only test failure is in the Window's build in TEST 'MLIR :: python/dialects/scf.py', which shouldn't be affected by these changes. I can try merging from main if we want to make it green before landing, otherwise is this good to merge in?

[Benjins]

Bumping this: if it's good to land, can someone with write access merge it?