https://github.com/Lancern created
https://github.com/llvm/llvm-project/pull/147200
This patch adds support for the following two builtin functions:
- `__builtin_bswap`, represented by the `cir.bswap` operation.
- `__builtin_bitreverse`, represented by the `cir.bit.reverse` operation.
>From 35ca85872ebc60f36f55c753c6aa33e00d94a91d Mon Sep 17 00:00:00 2001
From: Sirui Mu <msrlanc...@gmail.com>
Date: Mon, 7 Jul 2025 00:45:48 +0800
Subject: [PATCH] [CIR] Add bit reverse and byte reverse operations
---
clang/include/clang/CIR/Dialect/IR/CIROps.td | 49 ++++++++++
clang/lib/CIR/CodeGen/CIRGenBuiltin.cpp | 20 ++++
.../CIR/Lowering/DirectToLLVM/LowerToLLVM.cpp | 16 ++++
.../CIR/Lowering/DirectToLLVM/LowerToLLVM.h | 20 ++++
clang/test/CIR/CodeGen/builtin_bit.cpp | 91 +++++++++++++++++++
5 files changed, 196 insertions(+)
diff --git a/clang/include/clang/CIR/Dialect/IR/CIROps.td
b/clang/include/clang/CIR/Dialect/IR/CIROps.td
index 6529f1386599c..e26942d5cf511 100644
--- a/clang/include/clang/CIR/Dialect/IR/CIROps.td
+++ b/clang/include/clang/CIR/Dialect/IR/CIROps.td
@@ -2661,6 +2661,55 @@ def BitPopcountOp : CIR_BitOpBase<"bit.popcnt",
}];
}
+def BitReverseOp : CIR_BitOpBase<"bit.reverse", CIR_UIntOfWidths<[8, 16, 32,
64]>> {
+ let summary = "Reverse the bit pattern of the operand integer";
+ let description = [{
+ The `cir.bit.reverse` operation reverses the bits of the operand integer.
+ Its only argument must be of unsigned integer types of width 8, 16, 32, or
+ 64.
+
+ This operation covers the C/C++ builtin function `__builtin_bitreverse`.
+
+ Example:
+
+ ```mlir
+ %1 = cir.bit.reverse %0 : !u32i
+ ```
+ }];
+}
+
+//===----------------------------------------------------------------------===//
+// ByteswapOp
+//===----------------------------------------------------------------------===//
+
+def ByteSwapOp : CIR_Op<"bswap", [Pure, SameOperandsAndResultType]> {
+ let summary = "Reverse the bytes in the object representation of the
operand";
+ let description = [{
+ The `cir.bswap` operation takes an integer as operand, reverse the bytes in
+ the object representation of the operand integer, and returns the result.
+
+ The operand integer must be an unsigned integer. Its widths must be either
+ 16, 32, or 64.
+
+ Example:
+
+ ```mlir
+ // %0 = 0x12345678
+ %0 = cir.const #cir.int<305419896> : !u32i
+
+ // %1 should be 0x78563412
+ %1 = cir.bswap(%0 : !u32i) : !u32i
+ ```
+ }];
+
+ let results = (outs CIR_IntType:$result);
+ let arguments = (ins CIR_UIntOfWidths<[16, 32, 64]>:$input);
+
+ let assemblyFormat = [{
+ `(` $input `:` type($input) `)` `:` type($result) attr-dict
+ }];
+}
+
//===----------------------------------------------------------------------===//
// Assume Operations
//===----------------------------------------------------------------------===//
diff --git a/clang/lib/CIR/CodeGen/CIRGenBuiltin.cpp
b/clang/lib/CIR/CodeGen/CIRGenBuiltin.cpp
index fb046533a91b8..6c90bb7975630 100644
--- a/clang/lib/CIR/CodeGen/CIRGenBuiltin.cpp
+++ b/clang/lib/CIR/CodeGen/CIRGenBuiltin.cpp
@@ -190,6 +190,26 @@ RValue CIRGenFunction::emitBuiltinExpr(const GlobalDecl
&gd, unsigned builtinID,
expectedValue, probAttr);
return RValue::get(result);
}
+
+ case Builtin::BI__builtin_bswap16:
+ case Builtin::BI__builtin_bswap32:
+ case Builtin::BI__builtin_bswap64:
+ case Builtin::BI_byteswap_ushort:
+ case Builtin::BI_byteswap_ulong:
+ case Builtin::BI_byteswap_uint64: {
+ mlir::Value arg = emitScalarExpr(e->getArg(0));
+ return RValue::get(
+ builder.create<cir::ByteSwapOp>(getLoc(e->getSourceRange()), arg));
+ }
+
+ case Builtin::BI__builtin_bitreverse8:
+ case Builtin::BI__builtin_bitreverse16:
+ case Builtin::BI__builtin_bitreverse32:
+ case Builtin::BI__builtin_bitreverse64: {
+ mlir::Value arg = emitScalarExpr(e->getArg(0));
+ return RValue::get(
+ builder.create<cir::BitReverseOp>(getLoc(e->getSourceRange()), arg));
+ }
}
cgm.errorNYI(e->getSourceRange(), "unimplemented builtin call");
diff --git a/clang/lib/CIR/Lowering/DirectToLLVM/LowerToLLVM.cpp
b/clang/lib/CIR/Lowering/DirectToLLVM/LowerToLLVM.cpp
index 5ac42b6a63b09..acbaae1d227d0 100644
--- a/clang/lib/CIR/Lowering/DirectToLLVM/LowerToLLVM.cpp
+++ b/clang/lib/CIR/Lowering/DirectToLLVM/LowerToLLVM.cpp
@@ -535,6 +535,13 @@ mlir::LogicalResult
CIRToLLVMBitPopcountOpLowering::matchAndRewrite(
return mlir::LogicalResult::success();
}
+mlir::LogicalResult CIRToLLVMBitReverseOpLowering::matchAndRewrite(
+ cir::BitReverseOp op, OpAdaptor adaptor,
+ mlir::ConversionPatternRewriter &rewriter) const {
+ rewriter.replaceOpWithNewOp<mlir::LLVM::BitReverseOp>(op,
adaptor.getInput());
+ return mlir::success();
+}
+
mlir::LogicalResult CIRToLLVMBrCondOpLowering::matchAndRewrite(
cir::BrCondOp brOp, OpAdaptor adaptor,
mlir::ConversionPatternRewriter &rewriter) const {
@@ -551,6 +558,13 @@ mlir::LogicalResult
CIRToLLVMBrCondOpLowering::matchAndRewrite(
return mlir::success();
}
+mlir::LogicalResult CIRToLLVMByteSwapOpLowering::matchAndRewrite(
+ cir::ByteSwapOp op, OpAdaptor adaptor,
+ mlir::ConversionPatternRewriter &rewriter) const {
+ rewriter.replaceOpWithNewOp<mlir::LLVM::ByteSwapOp>(op, adaptor.getInput());
+ return mlir::LogicalResult::success();
+}
+
mlir::Type CIRToLLVMCastOpLowering::convertTy(mlir::Type ty) const {
return getTypeConverter()->convertType(ty);
}
@@ -2035,8 +2049,10 @@ void ConvertCIRToLLVMPass::runOnOperation() {
CIRToLLVMBitCtzOpLowering,
CIRToLLVMBitParityOpLowering,
CIRToLLVMBitPopcountOpLowering,
+ CIRToLLVMBitReverseOpLowering,
CIRToLLVMBrCondOpLowering,
CIRToLLVMBrOpLowering,
+ CIRToLLVMByteSwapOpLowering,
CIRToLLVMCallOpLowering,
CIRToLLVMCmpOpLowering,
CIRToLLVMComplexCreateOpLowering,
diff --git a/clang/lib/CIR/Lowering/DirectToLLVM/LowerToLLVM.h
b/clang/lib/CIR/Lowering/DirectToLLVM/LowerToLLVM.h
index d9fb91066317b..83e692d6dcbac 100644
--- a/clang/lib/CIR/Lowering/DirectToLLVM/LowerToLLVM.h
+++ b/clang/lib/CIR/Lowering/DirectToLLVM/LowerToLLVM.h
@@ -94,6 +94,16 @@ class CIRToLLVMBitPopcountOpLowering
mlir::ConversionPatternRewriter &) const override;
};
+class CIRToLLVMBitReverseOpLowering
+ : public mlir::OpConversionPattern<cir::BitReverseOp> {
+public:
+ using mlir::OpConversionPattern<cir::BitReverseOp>::OpConversionPattern;
+
+ mlir::LogicalResult
+ matchAndRewrite(cir::BitReverseOp op, OpAdaptor,
+ mlir::ConversionPatternRewriter &) const override;
+};
+
class CIRToLLVMBrCondOpLowering
: public mlir::OpConversionPattern<cir::BrCondOp> {
public:
@@ -104,6 +114,16 @@ class CIRToLLVMBrCondOpLowering
mlir::ConversionPatternRewriter &) const override;
};
+class CIRToLLVMByteSwapOpLowering
+ : public mlir::OpConversionPattern<cir::ByteSwapOp> {
+public:
+ using mlir::OpConversionPattern<cir::ByteSwapOp>::OpConversionPattern;
+
+ mlir::LogicalResult
+ matchAndRewrite(cir::ByteSwapOp op, OpAdaptor,
+ mlir::ConversionPatternRewriter &) const override;
+};
+
class CIRToLLVMCastOpLowering : public mlir::OpConversionPattern<cir::CastOp> {
mlir::DataLayout const &dataLayout;
diff --git a/clang/test/CIR/CodeGen/builtin_bit.cpp
b/clang/test/CIR/CodeGen/builtin_bit.cpp
index ba56c91ce7401..55377ce3b80fa 100644
--- a/clang/test/CIR/CodeGen/builtin_bit.cpp
+++ b/clang/test/CIR/CodeGen/builtin_bit.cpp
@@ -325,3 +325,94 @@ int test_builtin_popcountg(unsigned x) {
// OGCG-LABEL: _Z22test_builtin_popcountgj
// OGCG: %{{.+}} = call i32 @llvm.ctpop.i32(i32 %{{.+}})
+
+unsigned char test_builtin_bitreverse8(unsigned char x) {
+ return __builtin_bitreverse8(x);
+}
+
+// CIR-LABEL: @_Z24test_builtin_bitreverse8h
+// CIR: %{{.+}} = cir.bit.reverse(%{{.+}} : !u8i) : !u8i
+
+// LLVM-LABEL: @_Z24test_builtin_bitreverse8h
+// LLVM: %{{.+}} = call i8 @llvm.bitreverse.i8(i8 %{{.+}})
+
+// OGCG-LABEL: @_Z24test_builtin_bitreverse8h
+// OGCG: %{{.+}} = call i8 @llvm.bitreverse.i8(i8 %{{.+}})
+
+unsigned short test_builtin_bitreverse16(unsigned short x) {
+ return __builtin_bitreverse16(x);
+}
+
+// CIR-LABEL: @_Z25test_builtin_bitreverse16t
+// CIR: %{{.+}} = cir.bit.reverse(%{{.+}} : !u16i) : !u16i
+
+// LLVM-LABEL: @_Z25test_builtin_bitreverse16t
+// LLVM: %{{.+}} = call i16 @llvm.bitreverse.i16(i16 %{{.+}})
+
+// OGCG-LABEL: @_Z25test_builtin_bitreverse16t
+// OGCG: %{{.+}} = call i16 @llvm.bitreverse.i16(i16 %{{.+}})
+
+unsigned test_builtin_bitreverse32(unsigned x) {
+ return __builtin_bitreverse32(x);
+}
+
+// CIR-LABEL: @_Z25test_builtin_bitreverse32j
+// CIR: %{{.+}} = cir.bit.reverse(%{{.+}} : !u32i) : !u32i
+
+// LLVM-LABEL: @_Z25test_builtin_bitreverse32j
+// LLVM: %{{.+}} = call i32 @llvm.bitreverse.i32(i32 %{{.+}})
+
+// OGCG-LABEL: @_Z25test_builtin_bitreverse32j
+// OGCG: %{{.+}} = call i32 @llvm.bitreverse.i32(i32 %{{.+}})
+
+unsigned long long test_builtin_bitreverse64(unsigned long long x) {
+ return __builtin_bitreverse64(x);
+}
+
+// CIR-LABEL: @_Z25test_builtin_bitreverse64y
+// CIR: %{{.+}} = cir.bit.reverse(%{{.+}} : !u64i) : !u64i
+
+// LLVM-LABEL: @_Z25test_builtin_bitreverse64y
+// LLVM: %{{.+}} = call i64 @llvm.bitreverse.i64(i64 %{{.+}})
+
+// OGCG-LABEL: @_Z25test_builtin_bitreverse64y
+// OGCG: %{{.+}} = call i64 @llvm.bitreverse.i64(i64 %{{.+}})
+
+unsigned short test_builtin_bswap16(unsigned short x) {
+ return __builtin_bswap16(x);
+}
+
+// CIR-LABEL: @_Z20test_builtin_bswap16t
+// CIR: %{{.+}} = cir.bswap(%{{.+}} : !u16i) : !u16i
+
+// LLVM-LABEL: @_Z20test_builtin_bswap16t
+// LLVM: %{{.+}} = call i16 @llvm.bswap.i16(i16 %{{.+}})
+
+// OGCG-LABEL: @_Z20test_builtin_bswap16t
+// OGCG: %{{.+}} = call i16 @llvm.bswap.i16(i16 %{{.+}})
+
+unsigned test_builtin_bswap32(unsigned x) {
+ return __builtin_bswap32(x);
+}
+
+// CIR-LABEL: @_Z20test_builtin_bswap32j
+// CIR: %{{.+}} = cir.bswap(%{{.+}} : !u32i) : !u32i
+
+// LLVM-LABEL: @_Z20test_builtin_bswap32j
+// LLVM: %{{.+}} = call i32 @llvm.bswap.i32(i32 %{{.+}})
+
+// OGCG-LABEL: @_Z20test_builtin_bswap32j
+// OGCG: %{{.+}} = call i32 @llvm.bswap.i32(i32 %{{.+}})
+
+unsigned long long test_builtin_bswap64(unsigned long long x) {
+ return __builtin_bswap64(x);
+}
+
+// CIR-LABEL: @_Z20test_builtin_bswap64y
+// CIR: %{{.+}} = cir.bswap(%{{.+}} : !u64i) : !u64i
+
+// LLVM-LABEL: @_Z20test_builtin_bswap64y
+// LLVM: %{{.+}} = call i64 @llvm.bswap.i64(i64 %{{.+}})
+
+// OGCG-LABEL: @_Z20test_builtin_bswap64y
+// OGCG: %{{.+}} = call i64 @llvm.bswap.i64(i64 %{{.+}})
_______________________________________________
cfe-commits mailing list
cfe-commits@lists.llvm.org
https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
