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llvm-project/llvm/test/CodeGen/BPF/sanity.ll

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[bpf] rename triple names bpf_be -> bpfeb llvm-svn: 239162
2015-06-06 00:11:14 +08:00
; RUN: llc < %s -march=bpfel | FileCheck %s
BPF backend Summary: V8->V9: - cleanup tests V7->V8: - addressed feedback from David: - switched to range-based 'for' loops - fixed formatting of tests V6->V7: - rebased and adjusted AsmPrinter args - CamelCased .td, fixed formatting, cleaned up names, removed unused patterns - diffstat: 3 files changed, 203 insertions(+), 227 deletions(-) V5->V6: - addressed feedback from Chandler: - reinstated full verbose standard banner in all files - fixed variables that were not in CamelCase - fixed names of #ifdef in header files - removed redundant braces in if/else chains with single statements - fixed comments - removed trailing empty line - dropped debug annotations from tests - diffstat of these changes: 46 files changed, 456 insertions(+), 469 deletions(-) V4->V5: - fix setLoadExtAction() interface - clang-formated all where it made sense V3->V4: - added CODE_OWNERS entry for BPF backend V2->V3: - fix metadata in tests V1->V2: - addressed feedback from Tom and Matt - removed top level change to configure (now everything via 'experimental-backend') - reworked error reporting via DiagnosticInfo (similar to R600) - added few more tests - added cmake build - added Triple::bpf - tested on linux and darwin V1 cover letter: --------------------- recently linux gained "universal in-kernel virtual machine" which is called eBPF or extended BPF. The name comes from "Berkeley Packet Filter", since new instruction set is based on it. This patch adds a new backend that emits extended BPF instruction set. The concept and development are covered by the following articles: http://lwn.net/Articles/599755/ http://lwn.net/Articles/575531/ http://lwn.net/Articles/603983/ http://lwn.net/Articles/606089/ http://lwn.net/Articles/612878/ One of use cases: dtrace/systemtap alternative. bpf syscall manpage: https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=b4fc1a460f3017e958e6a8ea560ea0afd91bf6fe instruction set description and differences vs classic BPF: http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/tree/Documentation/networking/filter.txt Short summary of instruction set: - 64-bit registers R0 - return value from in-kernel function, and exit value for BPF program R1 - R5 - arguments from BPF program to in-kernel function R6 - R9 - callee saved registers that in-kernel function will preserve R10 - read-only frame pointer to access stack - two-operand instructions like +, -, *, mov, load/store - implicit prologue/epilogue (invisible stack pointer) - no floating point, no simd Short history of extended BPF in kernel: interpreter in 3.15, x64 JIT in 3.16, arm64 JIT, verifier, bpf syscall in 3.18, more to come in the future. It's a very small and simple backend. There is no support for global variables, arbitrary function calls, floating point, varargs, exceptions, indirect jumps, arbitrary pointer arithmetic, alloca, etc. From C front-end point of view it's very restricted. It's done on purpose, since kernel rejects all programs that it cannot prove safe. It rejects programs with loops and with memory accesses via arbitrary pointers. When kernel accepts the program it is guaranteed that program will terminate and will not crash the kernel. This patch implements all 'must have' bits. There are several things on TODO list, so this is not the end of development. Most of the code is a boiler plate code, copy-pasted from other backends. Only odd things are lack or < and <= instructions, specialized load_byte intrinsics and 'compare and goto' as single instruction. Current instruction set is fixed, but more instructions can be added in the future. Signed-off-by: Alexei Starovoitov <alexei.starovoitov@gmail.com> Subscribers: majnemer, chandlerc, echristo, joerg, pete, rengolin, kristof.beyls, arsenm, t.p.northover, tstellarAMD, aemerson, llvm-commits Differential Revision: http://reviews.llvm.org/D6494 llvm-svn: 227008
2015-01-25 01:51:26 +08:00
@foo_printf.fmt = private unnamed_addr constant [9 x i8] c"hello \0A\00", align 1
; Function Attrs: nounwind readnone uwtable
define i32 @foo_int(i32 %a, i32 %b) #0 {
%1 = add nsw i32 %b, %a
ret i32 %1
; CHECK-LABEL: foo_int:
convert bpf assembler to look like kernel verifier output since bpf instruction set was introduced people learned to read and understand kernel verifier output whereas llvm asm output stayed obscure and unknown. Convert llvm to emit assembler text similar to kernel to avoid this discrepancy Signed-off-by: Alexei Starovoitov <ast@kernel.org> llvm-svn: 287300
2016-11-18 10:32:35 +08:00
; CHECK: r2 += r1
BPF backend Summary: V8->V9: - cleanup tests V7->V8: - addressed feedback from David: - switched to range-based 'for' loops - fixed formatting of tests V6->V7: - rebased and adjusted AsmPrinter args - CamelCased .td, fixed formatting, cleaned up names, removed unused patterns - diffstat: 3 files changed, 203 insertions(+), 227 deletions(-) V5->V6: - addressed feedback from Chandler: - reinstated full verbose standard banner in all files - fixed variables that were not in CamelCase - fixed names of #ifdef in header files - removed redundant braces in if/else chains with single statements - fixed comments - removed trailing empty line - dropped debug annotations from tests - diffstat of these changes: 46 files changed, 456 insertions(+), 469 deletions(-) V4->V5: - fix setLoadExtAction() interface - clang-formated all where it made sense V3->V4: - added CODE_OWNERS entry for BPF backend V2->V3: - fix metadata in tests V1->V2: - addressed feedback from Tom and Matt - removed top level change to configure (now everything via 'experimental-backend') - reworked error reporting via DiagnosticInfo (similar to R600) - added few more tests - added cmake build - added Triple::bpf - tested on linux and darwin V1 cover letter: --------------------- recently linux gained "universal in-kernel virtual machine" which is called eBPF or extended BPF. The name comes from "Berkeley Packet Filter", since new instruction set is based on it. This patch adds a new backend that emits extended BPF instruction set. The concept and development are covered by the following articles: http://lwn.net/Articles/599755/ http://lwn.net/Articles/575531/ http://lwn.net/Articles/603983/ http://lwn.net/Articles/606089/ http://lwn.net/Articles/612878/ One of use cases: dtrace/systemtap alternative. bpf syscall manpage: https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=b4fc1a460f3017e958e6a8ea560ea0afd91bf6fe instruction set description and differences vs classic BPF: http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/tree/Documentation/networking/filter.txt Short summary of instruction set: - 64-bit registers R0 - return value from in-kernel function, and exit value for BPF program R1 - R5 - arguments from BPF program to in-kernel function R6 - R9 - callee saved registers that in-kernel function will preserve R10 - read-only frame pointer to access stack - two-operand instructions like +, -, *, mov, load/store - implicit prologue/epilogue (invisible stack pointer) - no floating point, no simd Short history of extended BPF in kernel: interpreter in 3.15, x64 JIT in 3.16, arm64 JIT, verifier, bpf syscall in 3.18, more to come in the future. It's a very small and simple backend. There is no support for global variables, arbitrary function calls, floating point, varargs, exceptions, indirect jumps, arbitrary pointer arithmetic, alloca, etc. From C front-end point of view it's very restricted. It's done on purpose, since kernel rejects all programs that it cannot prove safe. It rejects programs with loops and with memory accesses via arbitrary pointers. When kernel accepts the program it is guaranteed that program will terminate and will not crash the kernel. This patch implements all 'must have' bits. There are several things on TODO list, so this is not the end of development. Most of the code is a boiler plate code, copy-pasted from other backends. Only odd things are lack or < and <= instructions, specialized load_byte intrinsics and 'compare and goto' as single instruction. Current instruction set is fixed, but more instructions can be added in the future. Signed-off-by: Alexei Starovoitov <alexei.starovoitov@gmail.com> Subscribers: majnemer, chandlerc, echristo, joerg, pete, rengolin, kristof.beyls, arsenm, t.p.northover, tstellarAMD, aemerson, llvm-commits Differential Revision: http://reviews.llvm.org/D6494 llvm-svn: 227008
2015-01-25 01:51:26 +08:00
}
; Function Attrs: nounwind readnone uwtable
define signext i8 @foo_char(i8 signext %a, i8 signext %b) #0 {
%1 = add i8 %b, %a
ret i8 %1
; CHECK-LABEL: foo_char:
convert bpf assembler to look like kernel verifier output since bpf instruction set was introduced people learned to read and understand kernel verifier output whereas llvm asm output stayed obscure and unknown. Convert llvm to emit assembler text similar to kernel to avoid this discrepancy Signed-off-by: Alexei Starovoitov <ast@kernel.org> llvm-svn: 287300
2016-11-18 10:32:35 +08:00
; CHECK: r2 += r1
; CHECK: r2 <<= 56
; CHECK: r2 s>>= 56
BPF backend Summary: V8->V9: - cleanup tests V7->V8: - addressed feedback from David: - switched to range-based 'for' loops - fixed formatting of tests V6->V7: - rebased and adjusted AsmPrinter args - CamelCased .td, fixed formatting, cleaned up names, removed unused patterns - diffstat: 3 files changed, 203 insertions(+), 227 deletions(-) V5->V6: - addressed feedback from Chandler: - reinstated full verbose standard banner in all files - fixed variables that were not in CamelCase - fixed names of #ifdef in header files - removed redundant braces in if/else chains with single statements - fixed comments - removed trailing empty line - dropped debug annotations from tests - diffstat of these changes: 46 files changed, 456 insertions(+), 469 deletions(-) V4->V5: - fix setLoadExtAction() interface - clang-formated all where it made sense V3->V4: - added CODE_OWNERS entry for BPF backend V2->V3: - fix metadata in tests V1->V2: - addressed feedback from Tom and Matt - removed top level change to configure (now everything via 'experimental-backend') - reworked error reporting via DiagnosticInfo (similar to R600) - added few more tests - added cmake build - added Triple::bpf - tested on linux and darwin V1 cover letter: --------------------- recently linux gained "universal in-kernel virtual machine" which is called eBPF or extended BPF. The name comes from "Berkeley Packet Filter", since new instruction set is based on it. This patch adds a new backend that emits extended BPF instruction set. The concept and development are covered by the following articles: http://lwn.net/Articles/599755/ http://lwn.net/Articles/575531/ http://lwn.net/Articles/603983/ http://lwn.net/Articles/606089/ http://lwn.net/Articles/612878/ One of use cases: dtrace/systemtap alternative. bpf syscall manpage: https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=b4fc1a460f3017e958e6a8ea560ea0afd91bf6fe instruction set description and differences vs classic BPF: http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/tree/Documentation/networking/filter.txt Short summary of instruction set: - 64-bit registers R0 - return value from in-kernel function, and exit value for BPF program R1 - R5 - arguments from BPF program to in-kernel function R6 - R9 - callee saved registers that in-kernel function will preserve R10 - read-only frame pointer to access stack - two-operand instructions like +, -, *, mov, load/store - implicit prologue/epilogue (invisible stack pointer) - no floating point, no simd Short history of extended BPF in kernel: interpreter in 3.15, x64 JIT in 3.16, arm64 JIT, verifier, bpf syscall in 3.18, more to come in the future. It's a very small and simple backend. There is no support for global variables, arbitrary function calls, floating point, varargs, exceptions, indirect jumps, arbitrary pointer arithmetic, alloca, etc. From C front-end point of view it's very restricted. It's done on purpose, since kernel rejects all programs that it cannot prove safe. It rejects programs with loops and with memory accesses via arbitrary pointers. When kernel accepts the program it is guaranteed that program will terminate and will not crash the kernel. This patch implements all 'must have' bits. There are several things on TODO list, so this is not the end of development. Most of the code is a boiler plate code, copy-pasted from other backends. Only odd things are lack or < and <= instructions, specialized load_byte intrinsics and 'compare and goto' as single instruction. Current instruction set is fixed, but more instructions can be added in the future. Signed-off-by: Alexei Starovoitov <alexei.starovoitov@gmail.com> Subscribers: majnemer, chandlerc, echristo, joerg, pete, rengolin, kristof.beyls, arsenm, t.p.northover, tstellarAMD, aemerson, llvm-commits Differential Revision: http://reviews.llvm.org/D6494 llvm-svn: 227008
2015-01-25 01:51:26 +08:00
}
; Function Attrs: nounwind readnone uwtable
define i64 @foo_ll(i64 %a, i64 %b, i64 %c) #0 {
%1 = add nsw i64 %b, %a
%2 = sub i64 %1, %c
ret i64 %2
; CHECK-LABEL: foo_ll:
convert bpf assembler to look like kernel verifier output since bpf instruction set was introduced people learned to read and understand kernel verifier output whereas llvm asm output stayed obscure and unknown. Convert llvm to emit assembler text similar to kernel to avoid this discrepancy Signed-off-by: Alexei Starovoitov <ast@kernel.org> llvm-svn: 287300
2016-11-18 10:32:35 +08:00
; CHECK: r2 += r1
; CHECK: r2 -= r3
; CHECK: r0 = r2
BPF backend Summary: V8->V9: - cleanup tests V7->V8: - addressed feedback from David: - switched to range-based 'for' loops - fixed formatting of tests V6->V7: - rebased and adjusted AsmPrinter args - CamelCased .td, fixed formatting, cleaned up names, removed unused patterns - diffstat: 3 files changed, 203 insertions(+), 227 deletions(-) V5->V6: - addressed feedback from Chandler: - reinstated full verbose standard banner in all files - fixed variables that were not in CamelCase - fixed names of #ifdef in header files - removed redundant braces in if/else chains with single statements - fixed comments - removed trailing empty line - dropped debug annotations from tests - diffstat of these changes: 46 files changed, 456 insertions(+), 469 deletions(-) V4->V5: - fix setLoadExtAction() interface - clang-formated all where it made sense V3->V4: - added CODE_OWNERS entry for BPF backend V2->V3: - fix metadata in tests V1->V2: - addressed feedback from Tom and Matt - removed top level change to configure (now everything via 'experimental-backend') - reworked error reporting via DiagnosticInfo (similar to R600) - added few more tests - added cmake build - added Triple::bpf - tested on linux and darwin V1 cover letter: --------------------- recently linux gained "universal in-kernel virtual machine" which is called eBPF or extended BPF. The name comes from "Berkeley Packet Filter", since new instruction set is based on it. This patch adds a new backend that emits extended BPF instruction set. The concept and development are covered by the following articles: http://lwn.net/Articles/599755/ http://lwn.net/Articles/575531/ http://lwn.net/Articles/603983/ http://lwn.net/Articles/606089/ http://lwn.net/Articles/612878/ One of use cases: dtrace/systemtap alternative. bpf syscall manpage: https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=b4fc1a460f3017e958e6a8ea560ea0afd91bf6fe instruction set description and differences vs classic BPF: http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/tree/Documentation/networking/filter.txt Short summary of instruction set: - 64-bit registers R0 - return value from in-kernel function, and exit value for BPF program R1 - R5 - arguments from BPF program to in-kernel function R6 - R9 - callee saved registers that in-kernel function will preserve R10 - read-only frame pointer to access stack - two-operand instructions like +, -, *, mov, load/store - implicit prologue/epilogue (invisible stack pointer) - no floating point, no simd Short history of extended BPF in kernel: interpreter in 3.15, x64 JIT in 3.16, arm64 JIT, verifier, bpf syscall in 3.18, more to come in the future. It's a very small and simple backend. There is no support for global variables, arbitrary function calls, floating point, varargs, exceptions, indirect jumps, arbitrary pointer arithmetic, alloca, etc. From C front-end point of view it's very restricted. It's done on purpose, since kernel rejects all programs that it cannot prove safe. It rejects programs with loops and with memory accesses via arbitrary pointers. When kernel accepts the program it is guaranteed that program will terminate and will not crash the kernel. This patch implements all 'must have' bits. There are several things on TODO list, so this is not the end of development. Most of the code is a boiler plate code, copy-pasted from other backends. Only odd things are lack or < and <= instructions, specialized load_byte intrinsics and 'compare and goto' as single instruction. Current instruction set is fixed, but more instructions can be added in the future. Signed-off-by: Alexei Starovoitov <alexei.starovoitov@gmail.com> Subscribers: majnemer, chandlerc, echristo, joerg, pete, rengolin, kristof.beyls, arsenm, t.p.northover, tstellarAMD, aemerson, llvm-commits Differential Revision: http://reviews.llvm.org/D6494 llvm-svn: 227008
2015-01-25 01:51:26 +08:00
}
; Function Attrs: nounwind uwtable
define void @foo_call2(i32 %a, i32 %b) #1 {
%1 = trunc i32 %b to i8
tail call void @foo_2arg(i8 signext %1, i32 %a) #3
ret void
; CHECK-LABEL: foo_call2:
convert bpf assembler to look like kernel verifier output since bpf instruction set was introduced people learned to read and understand kernel verifier output whereas llvm asm output stayed obscure and unknown. Convert llvm to emit assembler text similar to kernel to avoid this discrepancy Signed-off-by: Alexei Starovoitov <ast@kernel.org> llvm-svn: 287300
2016-11-18 10:32:35 +08:00
; CHECK: r2 <<= 56
; CHECK: r2 s>>= 56
; CHECK: r1 = r2
BPF backend Summary: V8->V9: - cleanup tests V7->V8: - addressed feedback from David: - switched to range-based 'for' loops - fixed formatting of tests V6->V7: - rebased and adjusted AsmPrinter args - CamelCased .td, fixed formatting, cleaned up names, removed unused patterns - diffstat: 3 files changed, 203 insertions(+), 227 deletions(-) V5->V6: - addressed feedback from Chandler: - reinstated full verbose standard banner in all files - fixed variables that were not in CamelCase - fixed names of #ifdef in header files - removed redundant braces in if/else chains with single statements - fixed comments - removed trailing empty line - dropped debug annotations from tests - diffstat of these changes: 46 files changed, 456 insertions(+), 469 deletions(-) V4->V5: - fix setLoadExtAction() interface - clang-formated all where it made sense V3->V4: - added CODE_OWNERS entry for BPF backend V2->V3: - fix metadata in tests V1->V2: - addressed feedback from Tom and Matt - removed top level change to configure (now everything via 'experimental-backend') - reworked error reporting via DiagnosticInfo (similar to R600) - added few more tests - added cmake build - added Triple::bpf - tested on linux and darwin V1 cover letter: --------------------- recently linux gained "universal in-kernel virtual machine" which is called eBPF or extended BPF. The name comes from "Berkeley Packet Filter", since new instruction set is based on it. This patch adds a new backend that emits extended BPF instruction set. The concept and development are covered by the following articles: http://lwn.net/Articles/599755/ http://lwn.net/Articles/575531/ http://lwn.net/Articles/603983/ http://lwn.net/Articles/606089/ http://lwn.net/Articles/612878/ One of use cases: dtrace/systemtap alternative. bpf syscall manpage: https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=b4fc1a460f3017e958e6a8ea560ea0afd91bf6fe instruction set description and differences vs classic BPF: http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/tree/Documentation/networking/filter.txt Short summary of instruction set: - 64-bit registers R0 - return value from in-kernel function, and exit value for BPF program R1 - R5 - arguments from BPF program to in-kernel function R6 - R9 - callee saved registers that in-kernel function will preserve R10 - read-only frame pointer to access stack - two-operand instructions like +, -, *, mov, load/store - implicit prologue/epilogue (invisible stack pointer) - no floating point, no simd Short history of extended BPF in kernel: interpreter in 3.15, x64 JIT in 3.16, arm64 JIT, verifier, bpf syscall in 3.18, more to come in the future. It's a very small and simple backend. There is no support for global variables, arbitrary function calls, floating point, varargs, exceptions, indirect jumps, arbitrary pointer arithmetic, alloca, etc. From C front-end point of view it's very restricted. It's done on purpose, since kernel rejects all programs that it cannot prove safe. It rejects programs with loops and with memory accesses via arbitrary pointers. When kernel accepts the program it is guaranteed that program will terminate and will not crash the kernel. This patch implements all 'must have' bits. There are several things on TODO list, so this is not the end of development. Most of the code is a boiler plate code, copy-pasted from other backends. Only odd things are lack or < and <= instructions, specialized load_byte intrinsics and 'compare and goto' as single instruction. Current instruction set is fixed, but more instructions can be added in the future. Signed-off-by: Alexei Starovoitov <alexei.starovoitov@gmail.com> Subscribers: majnemer, chandlerc, echristo, joerg, pete, rengolin, kristof.beyls, arsenm, t.p.northover, tstellarAMD, aemerson, llvm-commits Differential Revision: http://reviews.llvm.org/D6494 llvm-svn: 227008
2015-01-25 01:51:26 +08:00
}
declare void @foo_2arg(i8 signext, i32) #2
; Function Attrs: nounwind uwtable
define i32 @foo_call5(i8 signext %a, i16 signext %b, i32 %c, i64 %d) #1 {
%1 = tail call i32 @bar(i8 signext %a, i16 signext %b, i32 %c, i64 %d) #3
ret i32 0
; CHECK-LABEL: foo_call5:
; CHECK: call bar
}
declare i32 @bar(i8 signext, i16 signext, i32, i64) #2
; Function Attrs: nounwind readnone uwtable
define signext i8 @foo_cmp(i8 signext %a, i8 signext %b) #0 {
%1 = icmp slt i8 %a, %b
%a.b = select i1 %1, i8 %a, i8 %b
ret i8 %a.b
; CHECK-LABEL: foo_cmp:
convert bpf assembler to look like kernel verifier output since bpf instruction set was introduced people learned to read and understand kernel verifier output whereas llvm asm output stayed obscure and unknown. Convert llvm to emit assembler text similar to kernel to avoid this discrepancy Signed-off-by: Alexei Starovoitov <ast@kernel.org> llvm-svn: 287300
2016-11-18 10:32:35 +08:00
; CHECK: if r2 s> r1
BPF backend Summary: V8->V9: - cleanup tests V7->V8: - addressed feedback from David: - switched to range-based 'for' loops - fixed formatting of tests V6->V7: - rebased and adjusted AsmPrinter args - CamelCased .td, fixed formatting, cleaned up names, removed unused patterns - diffstat: 3 files changed, 203 insertions(+), 227 deletions(-) V5->V6: - addressed feedback from Chandler: - reinstated full verbose standard banner in all files - fixed variables that were not in CamelCase - fixed names of #ifdef in header files - removed redundant braces in if/else chains with single statements - fixed comments - removed trailing empty line - dropped debug annotations from tests - diffstat of these changes: 46 files changed, 456 insertions(+), 469 deletions(-) V4->V5: - fix setLoadExtAction() interface - clang-formated all where it made sense V3->V4: - added CODE_OWNERS entry for BPF backend V2->V3: - fix metadata in tests V1->V2: - addressed feedback from Tom and Matt - removed top level change to configure (now everything via 'experimental-backend') - reworked error reporting via DiagnosticInfo (similar to R600) - added few more tests - added cmake build - added Triple::bpf - tested on linux and darwin V1 cover letter: --------------------- recently linux gained "universal in-kernel virtual machine" which is called eBPF or extended BPF. The name comes from "Berkeley Packet Filter", since new instruction set is based on it. This patch adds a new backend that emits extended BPF instruction set. The concept and development are covered by the following articles: http://lwn.net/Articles/599755/ http://lwn.net/Articles/575531/ http://lwn.net/Articles/603983/ http://lwn.net/Articles/606089/ http://lwn.net/Articles/612878/ One of use cases: dtrace/systemtap alternative. bpf syscall manpage: https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=b4fc1a460f3017e958e6a8ea560ea0afd91bf6fe instruction set description and differences vs classic BPF: http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/tree/Documentation/networking/filter.txt Short summary of instruction set: - 64-bit registers R0 - return value from in-kernel function, and exit value for BPF program R1 - R5 - arguments from BPF program to in-kernel function R6 - R9 - callee saved registers that in-kernel function will preserve R10 - read-only frame pointer to access stack - two-operand instructions like +, -, *, mov, load/store - implicit prologue/epilogue (invisible stack pointer) - no floating point, no simd Short history of extended BPF in kernel: interpreter in 3.15, x64 JIT in 3.16, arm64 JIT, verifier, bpf syscall in 3.18, more to come in the future. It's a very small and simple backend. There is no support for global variables, arbitrary function calls, floating point, varargs, exceptions, indirect jumps, arbitrary pointer arithmetic, alloca, etc. From C front-end point of view it's very restricted. It's done on purpose, since kernel rejects all programs that it cannot prove safe. It rejects programs with loops and with memory accesses via arbitrary pointers. When kernel accepts the program it is guaranteed that program will terminate and will not crash the kernel. This patch implements all 'must have' bits. There are several things on TODO list, so this is not the end of development. Most of the code is a boiler plate code, copy-pasted from other backends. Only odd things are lack or < and <= instructions, specialized load_byte intrinsics and 'compare and goto' as single instruction. Current instruction set is fixed, but more instructions can be added in the future. Signed-off-by: Alexei Starovoitov <alexei.starovoitov@gmail.com> Subscribers: majnemer, chandlerc, echristo, joerg, pete, rengolin, kristof.beyls, arsenm, t.p.northover, tstellarAMD, aemerson, llvm-commits Differential Revision: http://reviews.llvm.org/D6494 llvm-svn: 227008
2015-01-25 01:51:26 +08:00
}
; Function Attrs: nounwind readnone uwtable
define i32 @foo_muldiv(i8 signext %a, i16 signext %b, i32 %c, i64 %d) #0 {
%1 = icmp eq i8 %a, 0
br i1 %1, label %5, label %2
; <label>:2 ; preds = %0
%3 = sext i16 %b to i32
%4 = mul nsw i32 %3, %c
br label %8
; <label>:5 ; preds = %0
%6 = trunc i64 %d to i32
%7 = udiv i32 %6, %c
br label %8
; <label>:8 ; preds = %5, %2
%.0 = phi i32 [ %4, %2 ], [ %7, %5 ]
ret i32 %.0
; CHECK-LABEL: foo_muldiv:
convert bpf assembler to look like kernel verifier output since bpf instruction set was introduced people learned to read and understand kernel verifier output whereas llvm asm output stayed obscure and unknown. Convert llvm to emit assembler text similar to kernel to avoid this discrepancy Signed-off-by: Alexei Starovoitov <ast@kernel.org> llvm-svn: 287300
2016-11-18 10:32:35 +08:00
; CHECK: r2 *= r3
BPF backend Summary: V8->V9: - cleanup tests V7->V8: - addressed feedback from David: - switched to range-based 'for' loops - fixed formatting of tests V6->V7: - rebased and adjusted AsmPrinter args - CamelCased .td, fixed formatting, cleaned up names, removed unused patterns - diffstat: 3 files changed, 203 insertions(+), 227 deletions(-) V5->V6: - addressed feedback from Chandler: - reinstated full verbose standard banner in all files - fixed variables that were not in CamelCase - fixed names of #ifdef in header files - removed redundant braces in if/else chains with single statements - fixed comments - removed trailing empty line - dropped debug annotations from tests - diffstat of these changes: 46 files changed, 456 insertions(+), 469 deletions(-) V4->V5: - fix setLoadExtAction() interface - clang-formated all where it made sense V3->V4: - added CODE_OWNERS entry for BPF backend V2->V3: - fix metadata in tests V1->V2: - addressed feedback from Tom and Matt - removed top level change to configure (now everything via 'experimental-backend') - reworked error reporting via DiagnosticInfo (similar to R600) - added few more tests - added cmake build - added Triple::bpf - tested on linux and darwin V1 cover letter: --------------------- recently linux gained "universal in-kernel virtual machine" which is called eBPF or extended BPF. The name comes from "Berkeley Packet Filter", since new instruction set is based on it. This patch adds a new backend that emits extended BPF instruction set. The concept and development are covered by the following articles: http://lwn.net/Articles/599755/ http://lwn.net/Articles/575531/ http://lwn.net/Articles/603983/ http://lwn.net/Articles/606089/ http://lwn.net/Articles/612878/ One of use cases: dtrace/systemtap alternative. bpf syscall manpage: https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=b4fc1a460f3017e958e6a8ea560ea0afd91bf6fe instruction set description and differences vs classic BPF: http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/tree/Documentation/networking/filter.txt Short summary of instruction set: - 64-bit registers R0 - return value from in-kernel function, and exit value for BPF program R1 - R5 - arguments from BPF program to in-kernel function R6 - R9 - callee saved registers that in-kernel function will preserve R10 - read-only frame pointer to access stack - two-operand instructions like +, -, *, mov, load/store - implicit prologue/epilogue (invisible stack pointer) - no floating point, no simd Short history of extended BPF in kernel: interpreter in 3.15, x64 JIT in 3.16, arm64 JIT, verifier, bpf syscall in 3.18, more to come in the future. It's a very small and simple backend. There is no support for global variables, arbitrary function calls, floating point, varargs, exceptions, indirect jumps, arbitrary pointer arithmetic, alloca, etc. From C front-end point of view it's very restricted. It's done on purpose, since kernel rejects all programs that it cannot prove safe. It rejects programs with loops and with memory accesses via arbitrary pointers. When kernel accepts the program it is guaranteed that program will terminate and will not crash the kernel. This patch implements all 'must have' bits. There are several things on TODO list, so this is not the end of development. Most of the code is a boiler plate code, copy-pasted from other backends. Only odd things are lack or < and <= instructions, specialized load_byte intrinsics and 'compare and goto' as single instruction. Current instruction set is fixed, but more instructions can be added in the future. Signed-off-by: Alexei Starovoitov <alexei.starovoitov@gmail.com> Subscribers: majnemer, chandlerc, echristo, joerg, pete, rengolin, kristof.beyls, arsenm, t.p.northover, tstellarAMD, aemerson, llvm-commits Differential Revision: http://reviews.llvm.org/D6494 llvm-svn: 227008
2015-01-25 01:51:26 +08:00
}
; Function Attrs: nounwind uwtable
define i32 @foo_optimized() #1 {
%1 = tail call i32 @manyarg(i32 1, i32 2, i32 3, i32 4, i32 5) #3
ret i32 %1
; CHECK-LABEL: foo_optimized:
convert bpf assembler to look like kernel verifier output since bpf instruction set was introduced people learned to read and understand kernel verifier output whereas llvm asm output stayed obscure and unknown. Convert llvm to emit assembler text similar to kernel to avoid this discrepancy Signed-off-by: Alexei Starovoitov <ast@kernel.org> llvm-svn: 287300
2016-11-18 10:32:35 +08:00
; CHECK: r1 = 1
; CHECK: r2 = 2
; CHECK: r3 = 3
; CHECK: r4 = 4
; CHECK: r5 = 5
BPF backend Summary: V8->V9: - cleanup tests V7->V8: - addressed feedback from David: - switched to range-based 'for' loops - fixed formatting of tests V6->V7: - rebased and adjusted AsmPrinter args - CamelCased .td, fixed formatting, cleaned up names, removed unused patterns - diffstat: 3 files changed, 203 insertions(+), 227 deletions(-) V5->V6: - addressed feedback from Chandler: - reinstated full verbose standard banner in all files - fixed variables that were not in CamelCase - fixed names of #ifdef in header files - removed redundant braces in if/else chains with single statements - fixed comments - removed trailing empty line - dropped debug annotations from tests - diffstat of these changes: 46 files changed, 456 insertions(+), 469 deletions(-) V4->V5: - fix setLoadExtAction() interface - clang-formated all where it made sense V3->V4: - added CODE_OWNERS entry for BPF backend V2->V3: - fix metadata in tests V1->V2: - addressed feedback from Tom and Matt - removed top level change to configure (now everything via 'experimental-backend') - reworked error reporting via DiagnosticInfo (similar to R600) - added few more tests - added cmake build - added Triple::bpf - tested on linux and darwin V1 cover letter: --------------------- recently linux gained "universal in-kernel virtual machine" which is called eBPF or extended BPF. The name comes from "Berkeley Packet Filter", since new instruction set is based on it. This patch adds a new backend that emits extended BPF instruction set. The concept and development are covered by the following articles: http://lwn.net/Articles/599755/ http://lwn.net/Articles/575531/ http://lwn.net/Articles/603983/ http://lwn.net/Articles/606089/ http://lwn.net/Articles/612878/ One of use cases: dtrace/systemtap alternative. bpf syscall manpage: https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=b4fc1a460f3017e958e6a8ea560ea0afd91bf6fe instruction set description and differences vs classic BPF: http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/tree/Documentation/networking/filter.txt Short summary of instruction set: - 64-bit registers R0 - return value from in-kernel function, and exit value for BPF program R1 - R5 - arguments from BPF program to in-kernel function R6 - R9 - callee saved registers that in-kernel function will preserve R10 - read-only frame pointer to access stack - two-operand instructions like +, -, *, mov, load/store - implicit prologue/epilogue (invisible stack pointer) - no floating point, no simd Short history of extended BPF in kernel: interpreter in 3.15, x64 JIT in 3.16, arm64 JIT, verifier, bpf syscall in 3.18, more to come in the future. It's a very small and simple backend. There is no support for global variables, arbitrary function calls, floating point, varargs, exceptions, indirect jumps, arbitrary pointer arithmetic, alloca, etc. From C front-end point of view it's very restricted. It's done on purpose, since kernel rejects all programs that it cannot prove safe. It rejects programs with loops and with memory accesses via arbitrary pointers. When kernel accepts the program it is guaranteed that program will terminate and will not crash the kernel. This patch implements all 'must have' bits. There are several things on TODO list, so this is not the end of development. Most of the code is a boiler plate code, copy-pasted from other backends. Only odd things are lack or < and <= instructions, specialized load_byte intrinsics and 'compare and goto' as single instruction. Current instruction set is fixed, but more instructions can be added in the future. Signed-off-by: Alexei Starovoitov <alexei.starovoitov@gmail.com> Subscribers: majnemer, chandlerc, echristo, joerg, pete, rengolin, kristof.beyls, arsenm, t.p.northover, tstellarAMD, aemerson, llvm-commits Differential Revision: http://reviews.llvm.org/D6494 llvm-svn: 227008
2015-01-25 01:51:26 +08:00
}
declare i32 @manyarg(i32, i32, i32, i32, i32) #2
; Function Attrs: nounwind uwtable
define void @foo_printf() #1 {
%fmt = alloca [9 x i8], align 1
[opaque pointer type] Add textual IR support for explicit type parameter to getelementptr instruction One of several parallel first steps to remove the target type of pointers, replacing them with a single opaque pointer type. This adds an explicit type parameter to the gep instruction so that when the first parameter becomes an opaque pointer type, the type to gep through is still available to the instructions. * This doesn't modify gep operators, only instructions (operators will be handled separately) * Textual IR changes only. Bitcode (including upgrade) and changing the in-memory representation will be in separate changes. * geps of vectors are transformed as: getelementptr <4 x float*> %x, ... ->getelementptr float, <4 x float*> %x, ... Then, once the opaque pointer type is introduced, this will ultimately look like: getelementptr float, <4 x ptr> %x with the unambiguous interpretation that it is a vector of pointers to float. * address spaces remain on the pointer, not the type: getelementptr float addrspace(1)* %x ->getelementptr float, float addrspace(1)* %x Then, eventually: getelementptr float, ptr addrspace(1) %x Importantly, the massive amount of test case churn has been automated by same crappy python code. I had to manually update a few test cases that wouldn't fit the script's model (r228970,r229196,r229197,r229198). The python script just massages stdin and writes the result to stdout, I then wrapped that in a shell script to handle replacing files, then using the usual find+xargs to migrate all the files. update.py: import fileinput import sys import re ibrep = re.compile(r"(^.*?[^%\w]getelementptr inbounds )(((?:<\d* x )?)(.*?)(| addrspace\(\d\)) *\*(|>)(?:$| *(?:%|@|null|undef|blockaddress|getelementptr|addrspacecast|bitcast|inttoptr|\[\[[a-zA-Z]|\{\{).*$))") normrep = re.compile( r"(^.*?[^%\w]getelementptr )(((?:<\d* x )?)(.*?)(| addrspace\(\d\)) *\*(|>)(?:$| *(?:%|@|null|undef|blockaddress|getelementptr|addrspacecast|bitcast|inttoptr|\[\[[a-zA-Z]|\{\{).*$))") def conv(match, line): if not match: return line line = match.groups()[0] if len(match.groups()[5]) == 0: line += match.groups()[2] line += match.groups()[3] line += ", " line += match.groups()[1] line += "\n" return line for line in sys.stdin: if line.find("getelementptr ") == line.find("getelementptr inbounds"): if line.find("getelementptr inbounds") != line.find("getelementptr inbounds ("): line = conv(re.match(ibrep, line), line) elif line.find("getelementptr ") != line.find("getelementptr ("): line = conv(re.match(normrep, line), line) sys.stdout.write(line) apply.sh: for name in "$@" do python3 `dirname "$0"`/update.py < "$name" > "$name.tmp" && mv "$name.tmp" "$name" rm -f "$name.tmp" done The actual commands: From llvm/src: find test/ -name *.ll | xargs ./apply.sh From llvm/src/tools/clang: find test/ -name *.mm -o -name *.m -o -name *.cpp -o -name *.c | xargs -I '{}' ../../apply.sh "{}" From llvm/src/tools/polly: find test/ -name *.ll | xargs ./apply.sh After that, check-all (with llvm, clang, clang-tools-extra, lld, compiler-rt, and polly all checked out). The extra 'rm' in the apply.sh script is due to a few files in clang's test suite using interesting unicode stuff that my python script was throwing exceptions on. None of those files needed to be migrated, so it seemed sufficient to ignore those cases. Reviewers: rafael, dexonsmith, grosser Differential Revision: http://reviews.llvm.org/D7636 llvm-svn: 230786
2015-02-28 03:29:02 +08:00
%1 = getelementptr inbounds [9 x i8], [9 x i8]* %fmt, i64 0, i64 0
Revert "Change memcpy/memset/memmove to have dest and source alignments." This reverts commit r253511. This likely broke the bots in http://lab.llvm.org:8011/builders/clang-ppc64-elf-linux2/builds/20202 http://bb.pgr.jp/builders/clang-3stage-i686-linux/builds/3787 llvm-svn: 253543
2015-11-19 13:56:52 +08:00
call void @llvm.memcpy.p0i8.p0i8.i64(i8* %1, i8* getelementptr inbounds ([9 x i8], [9 x i8]* @foo_printf.fmt, i64 0, i64 0), i64 9, i32 1, i1 false)
BPF backend Summary: V8->V9: - cleanup tests V7->V8: - addressed feedback from David: - switched to range-based 'for' loops - fixed formatting of tests V6->V7: - rebased and adjusted AsmPrinter args - CamelCased .td, fixed formatting, cleaned up names, removed unused patterns - diffstat: 3 files changed, 203 insertions(+), 227 deletions(-) V5->V6: - addressed feedback from Chandler: - reinstated full verbose standard banner in all files - fixed variables that were not in CamelCase - fixed names of #ifdef in header files - removed redundant braces in if/else chains with single statements - fixed comments - removed trailing empty line - dropped debug annotations from tests - diffstat of these changes: 46 files changed, 456 insertions(+), 469 deletions(-) V4->V5: - fix setLoadExtAction() interface - clang-formated all where it made sense V3->V4: - added CODE_OWNERS entry for BPF backend V2->V3: - fix metadata in tests V1->V2: - addressed feedback from Tom and Matt - removed top level change to configure (now everything via 'experimental-backend') - reworked error reporting via DiagnosticInfo (similar to R600) - added few more tests - added cmake build - added Triple::bpf - tested on linux and darwin V1 cover letter: --------------------- recently linux gained "universal in-kernel virtual machine" which is called eBPF or extended BPF. The name comes from "Berkeley Packet Filter", since new instruction set is based on it. This patch adds a new backend that emits extended BPF instruction set. The concept and development are covered by the following articles: http://lwn.net/Articles/599755/ http://lwn.net/Articles/575531/ http://lwn.net/Articles/603983/ http://lwn.net/Articles/606089/ http://lwn.net/Articles/612878/ One of use cases: dtrace/systemtap alternative. bpf syscall manpage: https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=b4fc1a460f3017e958e6a8ea560ea0afd91bf6fe instruction set description and differences vs classic BPF: http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/tree/Documentation/networking/filter.txt Short summary of instruction set: - 64-bit registers R0 - return value from in-kernel function, and exit value for BPF program R1 - R5 - arguments from BPF program to in-kernel function R6 - R9 - callee saved registers that in-kernel function will preserve R10 - read-only frame pointer to access stack - two-operand instructions like +, -, *, mov, load/store - implicit prologue/epilogue (invisible stack pointer) - no floating point, no simd Short history of extended BPF in kernel: interpreter in 3.15, x64 JIT in 3.16, arm64 JIT, verifier, bpf syscall in 3.18, more to come in the future. It's a very small and simple backend. There is no support for global variables, arbitrary function calls, floating point, varargs, exceptions, indirect jumps, arbitrary pointer arithmetic, alloca, etc. From C front-end point of view it's very restricted. It's done on purpose, since kernel rejects all programs that it cannot prove safe. It rejects programs with loops and with memory accesses via arbitrary pointers. When kernel accepts the program it is guaranteed that program will terminate and will not crash the kernel. This patch implements all 'must have' bits. There are several things on TODO list, so this is not the end of development. Most of the code is a boiler plate code, copy-pasted from other backends. Only odd things are lack or < and <= instructions, specialized load_byte intrinsics and 'compare and goto' as single instruction. Current instruction set is fixed, but more instructions can be added in the future. Signed-off-by: Alexei Starovoitov <alexei.starovoitov@gmail.com> Subscribers: majnemer, chandlerc, echristo, joerg, pete, rengolin, kristof.beyls, arsenm, t.p.northover, tstellarAMD, aemerson, llvm-commits Differential Revision: http://reviews.llvm.org/D6494 llvm-svn: 227008
2015-01-25 01:51:26 +08:00
; CHECK-LABEL: foo_printf:
convert bpf assembler to look like kernel verifier output since bpf instruction set was introduced people learned to read and understand kernel verifier output whereas llvm asm output stayed obscure and unknown. Convert llvm to emit assembler text similar to kernel to avoid this discrepancy Signed-off-by: Alexei Starovoitov <ast@kernel.org> llvm-svn: 287300
2016-11-18 10:32:35 +08:00
; CHECK: r1 = 729618802566522216ll
[opaque pointer type] Add textual IR support for explicit type parameter to the call instruction See r230786 and r230794 for similar changes to gep and load respectively. Call is a bit different because it often doesn't have a single explicit type - usually the type is deduced from the arguments, and just the return type is explicit. In those cases there's no need to change the IR. When that's not the case, the IR usually contains the pointer type of the first operand - but since typed pointers are going away, that representation is insufficient so I'm just stripping the "pointerness" of the explicit type away. This does make the IR a bit weird - it /sort of/ reads like the type of the first operand: "call void () %x(" but %x is actually of type "void ()*" and will eventually be just of type "ptr". But this seems not too bad and I don't think it would benefit from repeating the type ("void (), void () * %x(" and then eventually "void (), ptr %x(") as has been done with gep and load. This also has a side benefit: since the explicit type is no longer a pointer, there's no ambiguity between an explicit type and a function that returns a function pointer. Previously this case needed an explicit type (eg: a function returning a void() function was written as "call void () () * @x(" rather than "call void () * @x(" because of the ambiguity between a function returning a pointer to a void() function and a function returning void). No ambiguity means even function pointer return types can just be written alone, without writing the whole function's type. This leaves /only/ the varargs case where the explicit type is required. Given the special type syntax in call instructions, the regex-fu used for migration was a bit more involved in its own unique way (as every one of these is) so here it is. Use it in conjunction with the apply.sh script and associated find/xargs commands I've provided in rr230786 to migrate your out of tree tests. Do let me know if any of this doesn't cover your cases & we can iterate on a more general script/regexes to help others with out of tree tests. About 9 test cases couldn't be automatically migrated - half of those were functions returning function pointers, where I just had to manually delete the function argument types now that we didn't need an explicit function type there. The other half were typedefs of function types used in calls - just had to manually drop the * from those. import fileinput import sys import re pat = re.compile(r'((?:=|:|^|\s)call\s(?:[^@]*?))(\s*$|\s*(?:(?:\[\[[a-zA-Z0-9_]+\]\]|[@%](?:(")?[\\\?@a-zA-Z0-9_.]*?(?(3)"|)|{{.*}}))(?:\(|$)|undef|inttoptr|bitcast|null|asm).*$)') addrspace_end = re.compile(r"addrspace\(\d+\)\s*\*$") func_end = re.compile("(?:void.*|\)\s*)\*$") def conv(match, line): if not match or re.search(addrspace_end, match.group(1)) or not re.search(func_end, match.group(1)): return line return line[:match.start()] + match.group(1)[:match.group(1).rfind('*')].rstrip() + match.group(2) + line[match.end():] for line in sys.stdin: sys.stdout.write(conv(re.search(pat, line), line)) llvm-svn: 235145
2015-04-17 07:24:18 +08:00
%2 = call i32 (i8*, ...) @printf(i8* %1) #3
BPF backend Summary: V8->V9: - cleanup tests V7->V8: - addressed feedback from David: - switched to range-based 'for' loops - fixed formatting of tests V6->V7: - rebased and adjusted AsmPrinter args - CamelCased .td, fixed formatting, cleaned up names, removed unused patterns - diffstat: 3 files changed, 203 insertions(+), 227 deletions(-) V5->V6: - addressed feedback from Chandler: - reinstated full verbose standard banner in all files - fixed variables that were not in CamelCase - fixed names of #ifdef in header files - removed redundant braces in if/else chains with single statements - fixed comments - removed trailing empty line - dropped debug annotations from tests - diffstat of these changes: 46 files changed, 456 insertions(+), 469 deletions(-) V4->V5: - fix setLoadExtAction() interface - clang-formated all where it made sense V3->V4: - added CODE_OWNERS entry for BPF backend V2->V3: - fix metadata in tests V1->V2: - addressed feedback from Tom and Matt - removed top level change to configure (now everything via 'experimental-backend') - reworked error reporting via DiagnosticInfo (similar to R600) - added few more tests - added cmake build - added Triple::bpf - tested on linux and darwin V1 cover letter: --------------------- recently linux gained "universal in-kernel virtual machine" which is called eBPF or extended BPF. The name comes from "Berkeley Packet Filter", since new instruction set is based on it. This patch adds a new backend that emits extended BPF instruction set. The concept and development are covered by the following articles: http://lwn.net/Articles/599755/ http://lwn.net/Articles/575531/ http://lwn.net/Articles/603983/ http://lwn.net/Articles/606089/ http://lwn.net/Articles/612878/ One of use cases: dtrace/systemtap alternative. bpf syscall manpage: https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=b4fc1a460f3017e958e6a8ea560ea0afd91bf6fe instruction set description and differences vs classic BPF: http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/tree/Documentation/networking/filter.txt Short summary of instruction set: - 64-bit registers R0 - return value from in-kernel function, and exit value for BPF program R1 - R5 - arguments from BPF program to in-kernel function R6 - R9 - callee saved registers that in-kernel function will preserve R10 - read-only frame pointer to access stack - two-operand instructions like +, -, *, mov, load/store - implicit prologue/epilogue (invisible stack pointer) - no floating point, no simd Short history of extended BPF in kernel: interpreter in 3.15, x64 JIT in 3.16, arm64 JIT, verifier, bpf syscall in 3.18, more to come in the future. It's a very small and simple backend. There is no support for global variables, arbitrary function calls, floating point, varargs, exceptions, indirect jumps, arbitrary pointer arithmetic, alloca, etc. From C front-end point of view it's very restricted. It's done on purpose, since kernel rejects all programs that it cannot prove safe. It rejects programs with loops and with memory accesses via arbitrary pointers. When kernel accepts the program it is guaranteed that program will terminate and will not crash the kernel. This patch implements all 'must have' bits. There are several things on TODO list, so this is not the end of development. Most of the code is a boiler plate code, copy-pasted from other backends. Only odd things are lack or < and <= instructions, specialized load_byte intrinsics and 'compare and goto' as single instruction. Current instruction set is fixed, but more instructions can be added in the future. Signed-off-by: Alexei Starovoitov <alexei.starovoitov@gmail.com> Subscribers: majnemer, chandlerc, echristo, joerg, pete, rengolin, kristof.beyls, arsenm, t.p.northover, tstellarAMD, aemerson, llvm-commits Differential Revision: http://reviews.llvm.org/D6494 llvm-svn: 227008
2015-01-25 01:51:26 +08:00
ret void
}
; Function Attrs: nounwind
Revert "Change memcpy/memset/memmove to have dest and source alignments." This reverts commit r253511. This likely broke the bots in http://lab.llvm.org:8011/builders/clang-ppc64-elf-linux2/builds/20202 http://bb.pgr.jp/builders/clang-3stage-i686-linux/builds/3787 llvm-svn: 253543
2015-11-19 13:56:52 +08:00
declare void @llvm.memcpy.p0i8.p0i8.i64(i8* nocapture, i8* nocapture, i64, i32, i1) #3
BPF backend Summary: V8->V9: - cleanup tests V7->V8: - addressed feedback from David: - switched to range-based 'for' loops - fixed formatting of tests V6->V7: - rebased and adjusted AsmPrinter args - CamelCased .td, fixed formatting, cleaned up names, removed unused patterns - diffstat: 3 files changed, 203 insertions(+), 227 deletions(-) V5->V6: - addressed feedback from Chandler: - reinstated full verbose standard banner in all files - fixed variables that were not in CamelCase - fixed names of #ifdef in header files - removed redundant braces in if/else chains with single statements - fixed comments - removed trailing empty line - dropped debug annotations from tests - diffstat of these changes: 46 files changed, 456 insertions(+), 469 deletions(-) V4->V5: - fix setLoadExtAction() interface - clang-formated all where it made sense V3->V4: - added CODE_OWNERS entry for BPF backend V2->V3: - fix metadata in tests V1->V2: - addressed feedback from Tom and Matt - removed top level change to configure (now everything via 'experimental-backend') - reworked error reporting via DiagnosticInfo (similar to R600) - added few more tests - added cmake build - added Triple::bpf - tested on linux and darwin V1 cover letter: --------------------- recently linux gained "universal in-kernel virtual machine" which is called eBPF or extended BPF. The name comes from "Berkeley Packet Filter", since new instruction set is based on it. This patch adds a new backend that emits extended BPF instruction set. The concept and development are covered by the following articles: http://lwn.net/Articles/599755/ http://lwn.net/Articles/575531/ http://lwn.net/Articles/603983/ http://lwn.net/Articles/606089/ http://lwn.net/Articles/612878/ One of use cases: dtrace/systemtap alternative. bpf syscall manpage: https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=b4fc1a460f3017e958e6a8ea560ea0afd91bf6fe instruction set description and differences vs classic BPF: http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/tree/Documentation/networking/filter.txt Short summary of instruction set: - 64-bit registers R0 - return value from in-kernel function, and exit value for BPF program R1 - R5 - arguments from BPF program to in-kernel function R6 - R9 - callee saved registers that in-kernel function will preserve R10 - read-only frame pointer to access stack - two-operand instructions like +, -, *, mov, load/store - implicit prologue/epilogue (invisible stack pointer) - no floating point, no simd Short history of extended BPF in kernel: interpreter in 3.15, x64 JIT in 3.16, arm64 JIT, verifier, bpf syscall in 3.18, more to come in the future. It's a very small and simple backend. There is no support for global variables, arbitrary function calls, floating point, varargs, exceptions, indirect jumps, arbitrary pointer arithmetic, alloca, etc. From C front-end point of view it's very restricted. It's done on purpose, since kernel rejects all programs that it cannot prove safe. It rejects programs with loops and with memory accesses via arbitrary pointers. When kernel accepts the program it is guaranteed that program will terminate and will not crash the kernel. This patch implements all 'must have' bits. There are several things on TODO list, so this is not the end of development. Most of the code is a boiler plate code, copy-pasted from other backends. Only odd things are lack or < and <= instructions, specialized load_byte intrinsics and 'compare and goto' as single instruction. Current instruction set is fixed, but more instructions can be added in the future. Signed-off-by: Alexei Starovoitov <alexei.starovoitov@gmail.com> Subscribers: majnemer, chandlerc, echristo, joerg, pete, rengolin, kristof.beyls, arsenm, t.p.northover, tstellarAMD, aemerson, llvm-commits Differential Revision: http://reviews.llvm.org/D6494 llvm-svn: 227008
2015-01-25 01:51:26 +08:00
; Function Attrs: nounwind
declare i32 @printf(i8* nocapture, ...) #4