[clang] f0c38ad - [Clang][SVE] Zero svcount_t directly rather than casting a svbool_t zero. (#217256)

[via cfe-commits]

Author: Paul Walker
Date: 2026-08-25T11:46:48+01:00
New Revision: f0c38ad37f5c6b32ad624d22891b4267e71d3a53

URL: https://github.com/llvm/llvm-project/commit/f0c38ad37f5c6b32ad624d22891b4267e71d3a53
DIFF: https://github.com/llvm/llvm-project/commit/f0c38ad37f5c6b32ad624d22891b4267e71d3a53.diff

LOG: [Clang][SVE] Zero svcount_t directly rather than casting a svbool_t zero. (#217256)

Added: 
    

Modified: 
    clang/lib/CodeGen/TargetBuiltins/ARM.cpp
    clang/test/CodeGen/AArch64/sve2p1-intrinsics/acle_sve2p1_pfalse.c

Removed: 
    


################################################################################
diff  --git a/clang/lib/CodeGen/TargetBuiltins/ARM.cpp b/clang/lib/CodeGen/TargetBuiltins/ARM.cpp
index 22e0dfc55157f..662ec6d549986 100644
--- a/clang/lib/CodeGen/TargetBuiltins/ARM.cpp
+++ b/clang/lib/CodeGen/TargetBuiltins/ARM.cpp
@@ -4226,12 +4226,8 @@ Value *CodeGenFunction::EmitAArch64SVEBuiltinExpr(unsigned BuiltinID,
   case SVE::BI__builtin_sve_svpfalse_b:
     return ConstantInt::getFalse(Ty);
 
-  case SVE::BI__builtin_sve_svpfalse_c: {
-    auto SVBoolTy = ScalableVectorType::get(Builder.getInt1Ty(), 16);
-    Function *CastToSVCountF =
-        CGM.getIntrinsic(Intrinsic::aarch64_sve_convert_from_svbool, Ty);
-    return Builder.CreateCall(CastToSVCountF, ConstantInt::getFalse(SVBoolTy));
-  }
+  case SVE::BI__builtin_sve_svpfalse_c:
+    return Constant::getNullValue(Ty);
 
   case SVE::BI__builtin_sve_svlen_bf16:
   case SVE::BI__builtin_sve_svlen_f16:

diff  --git a/clang/test/CodeGen/AArch64/sve2p1-intrinsics/acle_sve2p1_pfalse.c b/clang/test/CodeGen/AArch64/sve2p1-intrinsics/acle_sve2p1_pfalse.c
index fdf9c498341fa..6cbb561ebb00a 100644
--- a/clang/test/CodeGen/AArch64/sve2p1-intrinsics/acle_sve2p1_pfalse.c
+++ b/clang/test/CodeGen/AArch64/sve2p1-intrinsics/acle_sve2p1_pfalse.c
@@ -17,13 +17,11 @@
 
 // CHECK-LABEL: @test_svpfalse_c(
 // CHECK-NEXT:  entry:
-// CHECK-NEXT:    [[TMP0:%.*]] = tail call target("aarch64.svcount") @llvm.aarch64.sve.convert.from.svbool.taarch64.svcountt(<vscale x 16 x i1> zeroinitializer)
-// CHECK-NEXT:    ret target("aarch64.svcount") [[TMP0]]
+// CHECK-NEXT:    ret target("aarch64.svcount") zeroinitializer
 //
 // CPP-CHECK-LABEL: @_Z15test_svpfalse_cv(
 // CPP-CHECK-NEXT:  entry:
-// CPP-CHECK-NEXT:    [[TMP0:%.*]] = tail call target("aarch64.svcount") @llvm.aarch64.sve.convert.from.svbool.taarch64.svcountt(<vscale x 16 x i1> zeroinitializer)
-// CPP-CHECK-NEXT:    ret target("aarch64.svcount") [[TMP0]]
+// CPP-CHECK-NEXT:    ret target("aarch64.svcount") zeroinitializer
 //
 svcount_t test_svpfalse_c(void) ATTR
 {