From: Jan Wen Voung Date: Mon, 4 Oct 2010 17:32:41 +0000 (+0000) Subject: Add hook in MCSection to decide when to use "optimized nops", for each X-Git-Url: http://plrg.eecs.uci.edu/git/?a=commitdiff_plain;h=083cf1574facc9ce468fba1735c794bd7e520108;p=oota-llvm.git Add hook in MCSection to decide when to use "optimized nops", for each section kind. Previously, optimized nops were only used for MachO. Also added tests for ELF and COFF. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@115523 91177308-0d34-0410-b5e6-96231b3b80d8 --- diff --git a/include/llvm/MC/MCSection.h b/include/llvm/MC/MCSection.h index 5c997357c9d..3e5b5f13f32 100644 --- a/include/llvm/MC/MCSection.h +++ b/include/llvm/MC/MCSection.h @@ -61,6 +61,10 @@ namespace llvm { return false; } + // UseCodeAlign - Return true if a .align directive should use + // "optimized nops" to fill instead of 0s. + virtual bool UseCodeAlign() const = 0; + static bool classof(const MCSection *) { return true; } }; diff --git a/include/llvm/MC/MCSectionCOFF.h b/include/llvm/MC/MCSectionCOFF.h index f828e1060fe..62d07cf4368 100644 --- a/include/llvm/MC/MCSectionCOFF.h +++ b/include/llvm/MC/MCSectionCOFF.h @@ -55,6 +55,7 @@ namespace llvm { virtual void PrintSwitchToSection(const MCAsmInfo &MAI, raw_ostream &OS) const; + virtual bool UseCodeAlign() const; static bool classof(const MCSection *S) { return S->getVariant() == SV_COFF; diff --git a/include/llvm/MC/MCSectionELF.h b/include/llvm/MC/MCSectionELF.h index f97ab167118..a92d0f2c950 100644 --- a/include/llvm/MC/MCSectionELF.h +++ b/include/llvm/MC/MCSectionELF.h @@ -178,7 +178,8 @@ public: void PrintSwitchToSection(const MCAsmInfo &MAI, raw_ostream &OS) const; - + virtual bool UseCodeAlign() const; + /// isBaseAddressKnownZero - We know that non-allocatable sections (like /// debug info) have a base of zero. virtual bool isBaseAddressKnownZero() const { diff --git a/include/llvm/MC/MCSectionMachO.h b/include/llvm/MC/MCSectionMachO.h index 2d9d1333dbe..19d003a3b5a 100644 --- a/include/llvm/MC/MCSectionMachO.h +++ b/include/llvm/MC/MCSectionMachO.h @@ -165,6 +165,7 @@ public: virtual void PrintSwitchToSection(const MCAsmInfo &MAI, raw_ostream &OS) const; + virtual bool UseCodeAlign() const; static bool classof(const MCSection *S) { return S->getVariant() == SV_MachO; diff --git a/lib/MC/MCParser/AsmParser.cpp b/lib/MC/MCParser/AsmParser.cpp index fbac34a15ea..688827d2c76 100644 --- a/lib/MC/MCParser/AsmParser.cpp +++ b/lib/MC/MCParser/AsmParser.cpp @@ -1654,12 +1654,7 @@ bool AsmParser::ParseDirectiveAlign(bool IsPow2, unsigned ValueSize) { // Check whether we should use optimal code alignment for this .align // directive. - // - // FIXME: This should be using a target hook. - bool UseCodeAlign = false; - if (const MCSectionMachO *S = dyn_cast( - getStreamer().getCurrentSection())) - UseCodeAlign = S->hasAttribute(MCSectionMachO::S_ATTR_PURE_INSTRUCTIONS); + bool UseCodeAlign = getStreamer().getCurrentSection()->UseCodeAlign(); if ((!HasFillExpr || Lexer.getMAI().getTextAlignFillValue() == FillExpr) && ValueSize == 1 && UseCodeAlign) { getStreamer().EmitCodeAlignment(Alignment, MaxBytesToFill); diff --git a/lib/MC/MCSectionCOFF.cpp b/lib/MC/MCSectionCOFF.cpp index eb531600f72..0909df42227 100644 --- a/lib/MC/MCSectionCOFF.cpp +++ b/lib/MC/MCSectionCOFF.cpp @@ -74,3 +74,7 @@ void MCSectionCOFF::PrintSwitchToSection(const MCAsmInfo &MAI, } } } + +bool MCSectionCOFF::UseCodeAlign() const { + return getKind().isText(); +} diff --git a/lib/MC/MCSectionELF.cpp b/lib/MC/MCSectionELF.cpp index ef935d0c64b..133cad1b32c 100644 --- a/lib/MC/MCSectionELF.cpp +++ b/lib/MC/MCSectionELF.cpp @@ -112,6 +112,10 @@ void MCSectionELF::PrintSwitchToSection(const MCAsmInfo &MAI, OS << '\n'; } +bool MCSectionELF::UseCodeAlign() const { + return getFlags() & MCSectionELF::SHF_EXECINSTR; +} + // HasCommonSymbols - True if this section holds common symbols, this is // indicated on the ELF object file by a symbol with SHN_COMMON section // header index. diff --git a/lib/MC/MCSectionMachO.cpp b/lib/MC/MCSectionMachO.cpp index ded3b20eaf5..12b3efe663f 100644 --- a/lib/MC/MCSectionMachO.cpp +++ b/lib/MC/MCSectionMachO.cpp @@ -148,6 +148,10 @@ void MCSectionMachO::PrintSwitchToSection(const MCAsmInfo &MAI, OS << '\n'; } +bool MCSectionMachO::UseCodeAlign() const { + return hasAttribute(MCSectionMachO::S_ATTR_PURE_INSTRUCTIONS); +} + /// StripSpaces - This removes leading and trailing spaces from the StringRef. static void StripSpaces(StringRef &Str) { while (!Str.empty() && isspace(Str[0])) @@ -283,4 +287,3 @@ std::string MCSectionMachO::ParseSectionSpecifier(StringRef Spec, // In. return ""; } - diff --git a/lib/Target/PIC16/PIC16Section.cpp b/lib/Target/PIC16/PIC16Section.cpp index 2505b111f1e..7664fbbb7d4 100644 --- a/lib/Target/PIC16/PIC16Section.cpp +++ b/lib/Target/PIC16/PIC16Section.cpp @@ -102,3 +102,7 @@ void PIC16Section::PrintSwitchToSection(const MCAsmInfo &MAI, OS << '\n'; } + +bool PIC16Section::UseCodeAlign() const { + return isCODE_Type(); +} diff --git a/lib/Target/PIC16/PIC16Section.h b/lib/Target/PIC16/PIC16Section.h index 5b33b51a386..98e590229bd 100644 --- a/lib/Target/PIC16/PIC16Section.h +++ b/lib/Target/PIC16/PIC16Section.h @@ -88,6 +88,8 @@ namespace llvm { virtual void PrintSwitchToSection(const MCAsmInfo &MAI, raw_ostream &OS) const; + virtual bool UseCodeAlign() const; + static bool classof(const MCSection *S) { return S->getVariant() == SV_PIC16; } diff --git a/test/MC/COFF/align-nops.s b/test/MC/COFF/align-nops.s new file mode 100644 index 00000000000..f190fdb9a2d --- /dev/null +++ b/test/MC/COFF/align-nops.s @@ -0,0 +1,45 @@ +// RUN: llvm-mc -filetype=obj -triple i686-pc-win32 %s -o %t +// RUN: coff-dump.py %abs_tmp | FileCheck %s + +// Test that we get optimal nops in text + .text +f0: + .long 0 + .align 8, 0x90 + .long 0 + .align 8 + +// But not in another section + .data + .long 0 + .align 8, 0x90 + .long 0 + .align 8 + +//CHECK: Name = .text +//CHECK-NEXT: VirtualSize +//CHECK-NEXT: VirtualAddress +//CHECK-NEXT: SizeOfRawData = 16 +//CHECK-NEXT: PointerToRawData +//CHECK-NEXT: PointerToRelocations +//CHECK-NEXT: PointerToLineNumbers +//CHECK-NEXT: NumberOfRelocations +//CHECK-NEXT: NumberOfLineNumbers +//CHECK-NEXT: Charateristics = 0x400001 +//CHECK-NEXT: IMAGE_SCN_ALIGN_8BYTES +//CHECK-NEXT: SectionData = +//CHECK-NEXT: 00 00 00 00 0F 1F 40 00 - 00 00 00 00 0F 1F 40 00 + +//CHECK: Name = .data +//CHECK-NEXT: VirtualSize +//CHECK-NEXT: VirtualAddress +//CHECK-NEXT: SizeOfRawData = 16 +//CHECK-NEXT: PointerToRawData +//CHECK-NEXT: PointerToRelocations +//CHECK-NEXT: PointerToLineNumbers +//CHECK-NEXT: NumberOfRelocations +//CHECK-NEXT: NumberOfLineNumbers +//CHECK-NEXT: Charateristics = 0x400001 +//CHECK-NEXT: IMAGE_SCN_ALIGN_8BYTES +//CHECK-NEXT: SectionData = +//CHECK-NEXT: 00 00 00 00 90 90 90 90 - 00 00 00 00 00 00 00 00 diff --git a/test/MC/COFF/dg.exp b/test/MC/COFF/dg.exp index 7b7bd4e7380..d46d700975e 100644 --- a/test/MC/COFF/dg.exp +++ b/test/MC/COFF/dg.exp @@ -1,5 +1,5 @@ load_lib llvm.exp if { [llvm_supports_target X86] } { - RunLLVMTests [lsort [glob -nocomplain $srcdir/$subdir/*.{ll}]] + RunLLVMTests [lsort [glob -nocomplain $srcdir/$subdir/*.{ll,s}]] } diff --git a/test/MC/ELF/align-nops.s b/test/MC/ELF/align-nops.s new file mode 100644 index 00000000000..b6793ecb675 --- /dev/null +++ b/test/MC/ELF/align-nops.s @@ -0,0 +1,40 @@ +// RUN: llvm-mc -filetype=obj -triple x86_64-pc-linux-gnu %s -o - | elf-dump --dump-section-data | FileCheck %s + +// Test that we get optimal nops in text + .text +f0: + .long 0 + .align 8, 0x90 + .long 0 + .align 8 + +// But not in another section + .data + .long 0 + .align 8, 0x90 + .long 0 + .align 8 + +// CHECK: (('sh_name', 1) # '.text' +// CHECK-NEXT: ('sh_type', 1) +// CHECK-NEXT: ('sh_flags', 6) +// CHECK-NEXT: ('sh_addr', +// CHECK-NEXT: ('sh_offset', +// CHECK-NEXT: ('sh_size', 16) +// CHECK-NEXT: ('sh_link', 0) +// CHECK-NEXT: ('sh_info', 0) +// CHECK-NEXT: ('sh_addralign', 8) +// CHECK-NEXT: ('sh_entsize', 0) +// CHECK-NEXT: ('_section_data', '00000000 0f1f4000 00000000 0f1f4000') + +// CHECK: (('sh_name', 7) # '.data' +// CHECK-NEXT: ('sh_type', 1) +// CHECK-NEXT: ('sh_flags', 3) +// CHECK-NEXT: ('sh_addr', +// CHECK-NEXT: ('sh_offset', +// CHECK-NEXT: ('sh_size', 16) +// CHECK-NEXT: ('sh_link', 0) +// CHECK-NEXT: ('sh_info', 0) +// CHECK-NEXT: ('sh_addralign', 8) +// CHECK-NEXT: ('sh_entsize', 0) +// CHECK-NEXT: ('_section_data', '00000000 90909090 00000000 00000000')