https://github.com/xakep8 updated https://github.com/llvm/llvm-project/pull/214931
>From 92b788bc02d91996ff986b3f3f54927bcf90ca64 Mon Sep 17 00:00:00 2001 From: Kunal Dubey <[email protected]> Date: Sat, 8 Aug 2026 10:19:23 +0530 Subject: [PATCH 1/4] [CIR] Lowering __builtin_stdc_trailing_zeros Added CIRGen support for __builtin_stdc_trailing_zeros by lowering it to cir.ctz with zero behaviour defined, matching with the C23 stdbit semantics. Added CodeGen test for the same. --- clang/lib/CIR/CodeGen/CIRGenBuiltin.cpp | 7 +++++++ clang/test/CIR/CodeGenBuiltins/builtin-stdc-bit.c | 10 ++++++++++ 2 files changed, 17 insertions(+) create mode 100644 clang/test/CIR/CodeGenBuiltins/builtin-stdc-bit.c diff --git a/clang/lib/CIR/CodeGen/CIRGenBuiltin.cpp b/clang/lib/CIR/CodeGen/CIRGenBuiltin.cpp index 1efe2b81d5cae..2eb9d6c3bb661 100644 --- a/clang/lib/CIR/CodeGen/CIRGenBuiltin.cpp +++ b/clang/lib/CIR/CodeGen/CIRGenBuiltin.cpp @@ -1247,6 +1247,13 @@ RValue CIRGenFunction::emitBuiltinExpr(const GlobalDecl &gd, unsigned builtinID, getTarget().isCLZForZeroUndef()); case Builtin::BI__builtin_ctzg: return emitBuiltinBitOpWithFallback<cir::BitCtzOp>(*this, e); + case Builtin::BIstdc_trailing_zeros_uc: + case Builtin::BIstdc_trailing_zeros_us: + case Builtin::BIstdc_trailiing_zeros_ui: + case Builtin::BIstdc_trailing_zeros_ul: + case Builtin::BIstdc_trailing_zeros_ull: + case Builtin::BI__builtin_stdc_trailing_zeros: + return emitBuiltinBitOp<cir::BitCtzOp>(*this, e, /*poisonZero=*/false); case Builtin::BI__builtin_clzs: case Builtin::BI__builtin_clz: diff --git a/clang/test/CIR/CodeGenBuiltins/builtin-stdc-bit.c b/clang/test/CIR/CodeGenBuiltins/builtin-stdc-bit.c new file mode 100644 index 0000000000000..6d285c259a96f --- /dev/null +++ b/clang/test/CIR/CodeGenBuiltins/builtin-stdc-bit.c @@ -0,0 +1,10 @@ +// RUN: %clang_cc1 -triple x86_64-unknown-linux-gnu -fclangir -emit-cir %s -o - | FileCheck %s + +void test_stdc_trailing_zeros(unsigned long long x) { + int cnt = __builtin_stdc_trailing_zeros(x); + (void)cnt; +} + +// CHECK-LABEL: test_stdc_trailing_zeros +// CHECK: cir.ctz +// CHECK-NOT: poison_zero >From 06447c7643d7cb9a65d533d440b98411b6d02299 Mon Sep 17 00:00:00 2001 From: Kunal Dubey <[email protected]> Date: Sat, 8 Aug 2026 11:31:41 +0530 Subject: [PATCH 2/4] [CIR] Lowering __builtin_stdc_leading_zeros Added CIRGen support for __builtin_stdc_leading_zeros by lowering to cir.clz with zero behaviour defined, matching C23 stdbit semantics. Added CodeGen test for the same. --- clang/lib/CIR/CodeGen/CIRGenBuiltin.cpp | 8 ++++++++ .../CIR/CodeGenBuiltins/builtin-stdc-bit.c | 19 +++++++++++++++++++ 2 files changed, 27 insertions(+) diff --git a/clang/lib/CIR/CodeGen/CIRGenBuiltin.cpp b/clang/lib/CIR/CodeGen/CIRGenBuiltin.cpp index 2eb9d6c3bb661..bbc82f33571d4 100644 --- a/clang/lib/CIR/CodeGen/CIRGenBuiltin.cpp +++ b/clang/lib/CIR/CodeGen/CIRGenBuiltin.cpp @@ -1255,6 +1255,14 @@ RValue CIRGenFunction::emitBuiltinExpr(const GlobalDecl &gd, unsigned builtinID, case Builtin::BI__builtin_stdc_trailing_zeros: return emitBuiltinBitOp<cir::BitCtzOp>(*this, e, /*poisonZero=*/false); + case Builtin::BIstdc_leading_zeros_uc: + case Builtin::BIstdc_leading_zeros_us: + case Builtin::BIstdc_leading_zeros_ui: + case Builtin::BIstdc_leading_zeros_ul: + case Builtin::BIstdc_leading_zeros_ull: + case Builtin::BI__builtin_stdc_leading_zeros: + return emitBuiltinBitOp<cir::BitClzOp>(*this, e, /*poisonZero=*/false); + case Builtin::BI__builtin_clzs: case Builtin::BI__builtin_clz: case Builtin::BI__builtin_clzl: diff --git a/clang/test/CIR/CodeGenBuiltins/builtin-stdc-bit.c b/clang/test/CIR/CodeGenBuiltins/builtin-stdc-bit.c index 6d285c259a96f..1f127821673d2 100644 --- a/clang/test/CIR/CodeGenBuiltins/builtin-stdc-bit.c +++ b/clang/test/CIR/CodeGenBuiltins/builtin-stdc-bit.c @@ -8,3 +8,22 @@ void test_stdc_trailing_zeros(unsigned long long x) { // CHECK-LABEL: test_stdc_trailing_zeros // CHECK: cir.ctz // CHECK-NOT: poison_zero +// CHECK: cir.return + +void test_stdc_leading_zeros(unsigned x) { + return __builtin_stdc_trailing_zeros(x); +} + +// CHECK-LABEL: test_stdc_leading_zeros +// CHECK: cir.clz +// CHECK-NOT: poison_zero +// CHECK: cir.return + +void test_stdc_leading_zeros_ui(unsigned x) { + return stdc_leading_zeros_ui(x); +} + +// CHECK-LABEL: test_stdc_leading_zeros_ui +// CHECK: cir.clz +// CHECK-NOT: poison_zero +// CHECK: cir.return >From 7a91d44a11c0774d2c8f149eb66ee3593add00eb Mon Sep 17 00:00:00 2001 From: Kunal Dubey <[email protected]> Date: Sun, 9 Aug 2026 16:33:16 +0530 Subject: [PATCH 3/4] [CIR] Lowering __builtin_stdc_count_ones Added CIRGen support for lowering of __builtin_stdc_count_ones by lowering to cir.popcount, matching with the C23 stdbit semantics. Added test for the same. --- clang/lib/CIR/CodeGen/CIRGenBuiltin.cpp | 10 ++++++++- .../CIR/CodeGenBuiltins/builtin-stdc-bit.c | 22 ++++++++++++++++--- 2 files changed, 28 insertions(+), 4 deletions(-) diff --git a/clang/lib/CIR/CodeGen/CIRGenBuiltin.cpp b/clang/lib/CIR/CodeGen/CIRGenBuiltin.cpp index bbc82f33571d4..d27ace31cef78 100644 --- a/clang/lib/CIR/CodeGen/CIRGenBuiltin.cpp +++ b/clang/lib/CIR/CodeGen/CIRGenBuiltin.cpp @@ -1249,7 +1249,7 @@ RValue CIRGenFunction::emitBuiltinExpr(const GlobalDecl &gd, unsigned builtinID, return emitBuiltinBitOpWithFallback<cir::BitCtzOp>(*this, e); case Builtin::BIstdc_trailing_zeros_uc: case Builtin::BIstdc_trailing_zeros_us: - case Builtin::BIstdc_trailiing_zeros_ui: + case Builtin::BIstdc_trailing_zeros_ui: case Builtin::BIstdc_trailing_zeros_ul: case Builtin::BIstdc_trailing_zeros_ull: case Builtin::BI__builtin_stdc_trailing_zeros: @@ -1263,6 +1263,14 @@ RValue CIRGenFunction::emitBuiltinExpr(const GlobalDecl &gd, unsigned builtinID, case Builtin::BI__builtin_stdc_leading_zeros: return emitBuiltinBitOp<cir::BitClzOp>(*this, e, /*poisonZero=*/false); + case Builtin::BIstdc_count_ones_uc: + case Builtin::BIstdc_count_ones_us: + case Builtin::BIstdc_count_ones_ui: + case Builtin::BIstdc_count_ones_ul: + case Builtin::BIstdc_count_ones_ull: + case Builtin::BI__builtin_stdc_count_ones: + return emitBuiltinBitOp<cir::BitPopcountOp>(*this, e); + case Builtin::BI__builtin_clzs: case Builtin::BI__builtin_clz: case Builtin::BI__builtin_clzl: diff --git a/clang/test/CIR/CodeGenBuiltins/builtin-stdc-bit.c b/clang/test/CIR/CodeGenBuiltins/builtin-stdc-bit.c index 1f127821673d2..e9d5b25a10f0e 100644 --- a/clang/test/CIR/CodeGenBuiltins/builtin-stdc-bit.c +++ b/clang/test/CIR/CodeGenBuiltins/builtin-stdc-bit.c @@ -10,8 +10,8 @@ void test_stdc_trailing_zeros(unsigned long long x) { // CHECK-NOT: poison_zero // CHECK: cir.return -void test_stdc_leading_zeros(unsigned x) { - return __builtin_stdc_trailing_zeros(x); +unsigned test_stdc_leading_zeros(unsigned x) { + return __builtin_stdc_leading_zeros(x); } // CHECK-LABEL: test_stdc_leading_zeros @@ -19,7 +19,7 @@ void test_stdc_leading_zeros(unsigned x) { // CHECK-NOT: poison_zero // CHECK: cir.return -void test_stdc_leading_zeros_ui(unsigned x) { +unsigned test_stdc_leading_zeros_ui(unsigned x) { return stdc_leading_zeros_ui(x); } @@ -27,3 +27,19 @@ void test_stdc_leading_zeros_ui(unsigned x) { // CHECK: cir.clz // CHECK-NOT: poison_zero // CHECK: cir.return + +unsigned test_stdc_count_ones(unsigned x) { + return __builtin_stdc_count_ones(x); +} + +// CHECK-LABEL: test_stdc_count_ones +// CHECK: cir.popcount +// CHECK: cir.return + +unsigned test_stdc_count_ones_ui(unsigned x) { + return stdc_count_ones_ui(x); +} + +// CHECK-LABEL: test_stdc_count_ones_ui +// CHECK: cir.popcount +// CHECK: cir.return >From 5b211d8555808aac69e9c6f1d388c2dbd40daafb Mon Sep 17 00:00:00 2001 From: Kunal Dubey <[email protected]> Date: Mon, 10 Aug 2026 18:21:43 +0530 Subject: [PATCH 4/4] [CIR] Lowering __builtin_stdc_bit_width Added lowering for __builtin_stdc_bit_width by addition of helper emitStdcBitWidth that does integer type width minus leading zero count. Added tests for the same. --- clang/lib/CIR/CodeGen/CIRGenBuiltin.cpp | 28 +++++++++++++++++++ .../CIR/CodeGenBuiltins/builtin-stdc-bit.c | 24 +++++++++++++++- 2 files changed, 51 insertions(+), 1 deletion(-) diff --git a/clang/lib/CIR/CodeGen/CIRGenBuiltin.cpp b/clang/lib/CIR/CodeGen/CIRGenBuiltin.cpp index d27ace31cef78..aef5818084bc4 100644 --- a/clang/lib/CIR/CodeGen/CIRGenBuiltin.cpp +++ b/clang/lib/CIR/CodeGen/CIRGenBuiltin.cpp @@ -111,6 +111,26 @@ static RValue emitBuiltinBitOpWithFallback(CIRGenFunction &cgf, return RValue::get(builder.createSelect(loc, isZero, fallbackValue, result)); } +static RValue emitStdcBitWidth(CIRGenFunction &cfg, const CallExpr *e) { + CIRGenBuilderTy &builder = cfg.getBuilder(); + mlir::Location loc = cfg.getLoc(e->getSourceRange()); + + mlir::Value arg = cfg.emitScalarExpr(e->getArg(0)); + auto argTy = mlir::cast<cir::IntType>(arg.getType()); + + mlir::Value lz = + createBuiltinBitOp<cir::BitClzOp>(cfg, e, arg, /*poisonZero=*/false); + + mlir::Value width = builder.getConstInt(loc, argTy, argTy.getWidth()); + mlir::Value result = builder.createSub(loc, width, lz); + + mlir::Type resultTy = cfg.convertType(e->getType()); + if (result.getType() != resultTy) + result = builder.createIntCast(result, resultTy); + + return RValue::get(result); +} + /// Emit the conversions required to turn the given value into an /// integer of the given size. static mlir::Value emitToInt(CIRGenFunction &cgf, mlir::Value v, QualType t, @@ -1263,6 +1283,14 @@ RValue CIRGenFunction::emitBuiltinExpr(const GlobalDecl &gd, unsigned builtinID, case Builtin::BI__builtin_stdc_leading_zeros: return emitBuiltinBitOp<cir::BitClzOp>(*this, e, /*poisonZero=*/false); + case Builtin::BIstdc_bit_width_uc: + case Builtin::BIstdc_bit_width_us: + case Builtin::BIstdc_bit_width_ui: + case Builtin::BIstdc_bit_width_ul: + case Builtin::BIstdc_bit_width_ull: + case Builtin::BI__builtin_stdc_bit_width: + return emitStdcBitWidth(*this, e); + case Builtin::BIstdc_count_ones_uc: case Builtin::BIstdc_count_ones_us: case Builtin::BIstdc_count_ones_ui: diff --git a/clang/test/CIR/CodeGenBuiltins/builtin-stdc-bit.c b/clang/test/CIR/CodeGenBuiltins/builtin-stdc-bit.c index e9d5b25a10f0e..56632e70761ef 100644 --- a/clang/test/CIR/CodeGenBuiltins/builtin-stdc-bit.c +++ b/clang/test/CIR/CodeGenBuiltins/builtin-stdc-bit.c @@ -1,4 +1,6 @@ -// RUN: %clang_cc1 -triple x86_64-unknown-linux-gnu -fclangir -emit-cir %s -o - | FileCheck %s +// RUN: %clang_cc1 -triple x86_64-unknown-linux-gnu -std=c23 -I%S/../../CodeGen/Inputs -fclangir -emit-cir %s -o - | FileCheck %s + +#include <stdbit.h> void test_stdc_trailing_zeros(unsigned long long x) { int cnt = __builtin_stdc_trailing_zeros(x); @@ -43,3 +45,23 @@ unsigned test_stdc_count_ones_ui(unsigned x) { // CHECK-LABEL: test_stdc_count_ones_ui // CHECK: cir.popcount // CHECK: cir.return + +unsigned test_stdc_bit_width(unsigned x) { + return __builtin_stdc_bit_width(x); +} + +// CHECK-LABEL: test_stdc_bit_width +// CHECK: cir.clz +// CHECK-NOT: poison_zero +// CHECK: cir.sub +// CHECK: cir.return + +unsigned test_stdc_bit_width_ui(unsigned x) { + return stdc_bit_width_ui(x); +} + +// CHECK-LABEL: test_stdc_bit_width_ui +// CHECK: cir.clz +// CHECK-NOT: poison_zero +// CHECK: cir.sub +// CHECK: cir.return _______________________________________________ cfe-commits mailing list [email protected] https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
