https://github.com/Amichaxx created https://github.com/llvm/llvm-project/pull/149329
Issue originally raised in https://github.com/llvm/llvm-project/issues/71362#issuecomment-3028515618. Certain NEON intrinsics that operate on poly types (e.g. poly8x8_t) failed to compile with the -fno-lax-vector-conversions flag. This patch updates NeonEmitter.cpp to insert an explicit __builtin_bit_cast from poly types to the required signed integer vector types when generating lane-related intrinsics. A test 'neon-bitcast-poly.ll' is included. >From 2895e5e7b56c1c611b39a5c85de92d18f3aae71a Mon Sep 17 00:00:00 2001 From: Amina Chabane <amina.chab...@arm.com> Date: Tue, 15 Jul 2025 15:56:49 +0000 Subject: [PATCH 1/3] [AArch64][NEON] Fix poly lane intrinsics under -fno-lax-vector-conversions. Issue originally raised in https://github.com/llvm/llvm-project/issues/71362#issuecomment-3028515618. Certain NEON intrinsics that operate on poly types (e.g. poly8x8_t) failed to compile with the -fno-lax-vector-conversions flag. This patch updates NeonEmitter.cpp to insert an explicit __builtin_bit_cast from poly types to the required signed integer vector types when generating lane-based intrinsics. A test neon-bitcast-poly is included. --- clang/utils/TableGen/NeonEmitter.cpp | 10 +++- .../test/CodeGen/AArch64/neon-bitcast-poly.ll | 51 +++++++++++++++++++ 2 files changed, 60 insertions(+), 1 deletion(-) create mode 100644 llvm/test/CodeGen/AArch64/neon-bitcast-poly.ll diff --git a/clang/utils/TableGen/NeonEmitter.cpp b/clang/utils/TableGen/NeonEmitter.cpp index 409f1c4f71834..574a29d0e4dd9 100644 --- a/clang/utils/TableGen/NeonEmitter.cpp +++ b/clang/utils/TableGen/NeonEmitter.cpp @@ -1401,12 +1401,20 @@ void Intrinsic::emitBodyAsBuiltinCall() { if (LocalCK == ClassB || (T.isHalf() && !T.isScalarForMangling())) { CastToType.makeInteger(8, true); Arg = "__builtin_bit_cast(" + CastToType.str() + ", " + Arg + ")"; + } + else if ((T.isPoly() || + (T.isInteger() && !T.isSigned() && + StringRef(Name).contains("_p8")) || + StringRef(Name).contains("_p16") || + StringRef(Name).contains("_p64"))) { + CastToType.makeSigned(); + Arg = "__builtin_bit_cast(" + CastToType.str() + ", " + Arg + ")"; + } } else if (LocalCK == ClassI) { if (CastToType.isInteger()) { CastToType.makeSigned(); Arg = "__builtin_bit_cast(" + CastToType.str() + ", " + Arg + ")"; } - } } S += Arg + ", "; diff --git a/llvm/test/CodeGen/AArch64/neon-bitcast-poly.ll b/llvm/test/CodeGen/AArch64/neon-bitcast-poly.ll new file mode 100644 index 0000000000000..b577eb1e34b09 --- /dev/null +++ b/llvm/test/CodeGen/AArch64/neon-bitcast-poly.ll @@ -0,0 +1,51 @@ +; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py UTC_ARGS: --version 5 +; RUN: llc -mtriple=aarch64-linux-gnu -o - %s | FileCheck %s + +; This test verifies that NEON intrinsics using polynomial types (poly8/16/64) emit correct AArch64 instructions +; after bitcasting to signed integer vectors. These intrinsics would previously fail under -fno-lax-vector-conversions. + +define <8 x i8> @_Z18test_vcopy_lane_p811__Poly8x8_tS_(<8 x i8> %a, <8 x i8> %b) { +; CHECK-LABEL: _Z18test_vcopy_lane_p811__Poly8x8_tS_: +; CHECK: // %bb.0: // %entry +; CHECK-NEXT: // kill: def $d0 killed $d0 def $q0 +; CHECK-NEXT: // kill: def $d1 killed $d1 def $q1 +; CHECK-NEXT: mov v0.b[0], v1.b[0] +; CHECK-NEXT: // kill: def $d0 killed $d0 killed $q0 +; CHECK-NEXT: ret +entry: + %vset_lane = shufflevector <8 x i8> %b, <8 x i8> %a, <8 x i32> <i32 0, i32 9, i32 10, i32 11, i32 12, i32 13, i32 14, i32 15> + ret <8 x i8> %vset_lane +} + +define <4 x i16> @_Z18test_vset_lane_p16t12__Poly16x4_t(i16 %val, <4 x i16> %vec) { +; CHECK-LABEL: _Z18test_vset_lane_p16t12__Poly16x4_t: +; CHECK: // %bb.0: // %entry +; CHECK-NEXT: // kill: def $d0 killed $d0 def $q0 +; CHECK-NEXT: mov v0.h[0], w0 +; CHECK-NEXT: // kill: def $d0 killed $d0 killed $q0 +; CHECK-NEXT: ret +entry: + %vset_lane = insertelement <4 x i16> %vec, i16 %val, i64 0 + ret <4 x i16> %vset_lane +} + +define i64 @_Z18test_vget_lane_p6412__Poly64x1_t(<1 x i64> %vec){ +; CHECK-LABEL: _Z18test_vget_lane_p6412__Poly64x1_t: +; CHECK: // %bb.0: // %entry +; CHECK-NEXT: // kill: def $d0 killed $d0 def $q0 +; CHECK-NEXT: fmov x0, d0 +; CHECK-NEXT: ret +entry: + %vget_lane = extractelement <1 x i64> %vec, i64 0 + ret i64 %vget_lane +} + +define <16 x i8> @_Z18test_vsetq_lane_p8h12__Poly8x16_t(i8 %val, <16 x i8> %vec){ +; CHECK-LABEL: _Z18test_vsetq_lane_p8h12__Poly8x16_t: +; CHECK: // %bb.0: // %entry +; CHECK-NEXT: mov v0.b[0], w0 +; CHECK-NEXT: ret +entry: + %vset_lane = insertelement <16 x i8> %vec, i8 %val, i64 0 + ret <16 x i8> %vset_lane +} >From c300ab6ced97df16728fac0a07c94e38792a2047 Mon Sep 17 00:00:00 2001 From: Amina Chabane <amina.chab...@arm.com> Date: Wed, 16 Jul 2025 13:53:30 +0000 Subject: [PATCH 2/3] Added isVector() condition to avoid scalar constants. --- clang/utils/TableGen/NeonEmitter.cpp | 23 ++++++++++------------- 1 file changed, 10 insertions(+), 13 deletions(-) diff --git a/clang/utils/TableGen/NeonEmitter.cpp b/clang/utils/TableGen/NeonEmitter.cpp index 574a29d0e4dd9..d3dd1c5589920 100644 --- a/clang/utils/TableGen/NeonEmitter.cpp +++ b/clang/utils/TableGen/NeonEmitter.cpp @@ -1401,22 +1401,19 @@ void Intrinsic::emitBodyAsBuiltinCall() { if (LocalCK == ClassB || (T.isHalf() && !T.isScalarForMangling())) { CastToType.makeInteger(8, true); Arg = "__builtin_bit_cast(" + CastToType.str() + ", " + Arg + ")"; + } else if ((T.isPoly() || (T.isVector() && T.isInteger() && !T.isSigned() && + (StringRef(Name).contains("_p8") || + StringRef(Name).contains("_p16") || + StringRef(Name).contains("_p64"))))) { + CastToType.makeSigned(); + Arg = "__builtin_bit_cast(" + CastToType.str() + ", " + Arg + ")"; + } else if (LocalCK == ClassI && CastToType.isInteger()) { + CastToType.makeSigned(); + Arg = "__builtin_bit_cast(" + CastToType.str() + ", " + Arg + ")"; } - else if ((T.isPoly() || - (T.isInteger() && !T.isSigned() && - StringRef(Name).contains("_p8")) || - StringRef(Name).contains("_p16") || - StringRef(Name).contains("_p64"))) { - CastToType.makeSigned(); - Arg = "__builtin_bit_cast(" + CastToType.str() + ", " + Arg + ")"; - } - } else if (LocalCK == ClassI) { - if (CastToType.isInteger()) { - CastToType.makeSigned(); - Arg = "__builtin_bit_cast(" + CastToType.str() + ", " + Arg + ")"; - } } + S += Arg + ", "; } >From 102ca6f20dac9e2c5a458ee5e637e517f242c949 Mon Sep 17 00:00:00 2001 From: Amina Chabane <amina.chab...@arm.com> Date: Thu, 17 Jul 2025 14:42:43 +0000 Subject: [PATCH 3/3] Newline deletion --- clang/utils/TableGen/NeonEmitter.cpp | 8 +++----- 1 file changed, 3 insertions(+), 5 deletions(-) diff --git a/clang/utils/TableGen/NeonEmitter.cpp b/clang/utils/TableGen/NeonEmitter.cpp index d3dd1c5589920..1bd8c8b58c396 100644 --- a/clang/utils/TableGen/NeonEmitter.cpp +++ b/clang/utils/TableGen/NeonEmitter.cpp @@ -1402,9 +1402,9 @@ void Intrinsic::emitBodyAsBuiltinCall() { CastToType.makeInteger(8, true); Arg = "__builtin_bit_cast(" + CastToType.str() + ", " + Arg + ")"; } else if ((T.isPoly() || (T.isVector() && T.isInteger() && !T.isSigned() && - (StringRef(Name).contains("_p8") || - StringRef(Name).contains("_p16") || - StringRef(Name).contains("_p64"))))) { + (StringRef(Name).contains("_p8") || + StringRef(Name).contains("_p16") || + StringRef(Name).contains("_p64"))))) { CastToType.makeSigned(); Arg = "__builtin_bit_cast(" + CastToType.str() + ", " + Arg + ")"; } else if (LocalCK == ClassI && CastToType.isInteger()) { @@ -1412,8 +1412,6 @@ void Intrinsic::emitBodyAsBuiltinCall() { Arg = "__builtin_bit_cast(" + CastToType.str() + ", " + Arg + ")"; } } - - S += Arg + ", "; } _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
