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author | H.J. Lu <hjl.tools@gmail.com> | 2018-03-07 04:18:45 -0800 |
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committer | H.J. Lu <hjl.tools@gmail.com> | 2018-03-07 04:18:56 -0800 |
commit | 3ae729d5a4f63740ed9a778960b17c2912b0bbdd (patch) | |
tree | b186f154a1e58be2c572eaeef8e593715736467b /gas/doc | |
parent | 52fe4420b771a0f3b4fc7c6535bbd6e9b279f775 (diff) | |
download | gdb-3ae729d5a4f63740ed9a778960b17c2912b0bbdd.zip gdb-3ae729d5a4f63740ed9a778960b17c2912b0bbdd.tar.gz gdb-3ae729d5a4f63740ed9a778960b17c2912b0bbdd.tar.bz2 |
x86: Rewrite NOP generation for fill and alignment
Rewrite NOP generation for fill and code alignment by:
1. Add a 11-byte NOP with another 0x66 prefix.
2. Remove the multi-byte NOP entries which consist of 2 instructions.
3. Select proper NOPs based on ISA and processor tuning.
4. Generate multiple NOPs with the longer NOPs first followed by the
shorter NOP.
5. Use jump for larger NOP padding:
a. > 8 bytes (2 NOPs) in 16-bit mode.
b. > 14 bytes (2 NOPs) for older processors.
c. > 77 bytes (7 NOPs) for newer processors.
6. Update MAX_MEM_FOR_RS_ALIGN_CODE to 4095.
PR gas/22874
* config/tc-i386.c (f32_5): Removed.
(f32_8): Likewise.
(f32_9): Likewise.
(f32_10): Likewise.
(f32_11): Likewise.
(f32_12): Likewise.
(f32_13): Likewise.
(f32_14): Likewise.
(f16_5): Likewise.
(f16_6): Likewise.
(f16_7): Likewise.
(f16_8): Likewise.
(jump_31): Likewise.
(alt64_11): Likewise.
(alt64_patt): Likewise.
(jump_disp8): New.
(jump32_disp32): Likewise.
(jump16_disp32): Likewise.
(alt_11): Likewise.
(f32_patt): Updated.
(f16_patt): Likewise.
(alt_patt): Add alt_11.
(i386_align_code): Merged with ...
(i386_generate_nops): This. Rewritten.
(fits_in_imm7): Moved before i386_generate_nops.
(fits_in_imm31): Likewise.
* config/tc-i386.h (MAX_MEM_FOR_RS_ALIGN_CODE): Updated to
4095.
(i386_align_code): Removed.
(HANDLE_ALIGN): Rewritten with i386_generate_nops.
* doc/as.texinfo: Update limits of control byte for x86 .nops
directive.
* testsuite/gas/i386/i386.exp: Run nops-7 and x86-64-nops-7.
* gas/testsuite/gas/i386/noavx-3.l: Updated.
* gas/testsuite/gas/i386/nop-1.d: Likewise.
* gas/testsuite/gas/i386/nop-1.s: Likewise.
* gas/testsuite/gas/i386/nop-2.d: Likewise.
* gas/testsuite/gas/i386/nop-2.s: Likewise.
* gas/testsuite/gas/i386/nop-3.d: Likewise.
* gas/testsuite/gas/i386/nop-4.d: Likewise.
* gas/testsuite/gas/i386/nop-5.d: Likewise.
* gas/testsuite/gas/i386/nop-5.s: Likewise.
* gas/testsuite/gas/i386/nop-6.d: Likewise.
* gas/testsuite/gas/i386/nop-bad-1.l: Likewise.
* gas/testsuite/gas/i386/nops-1-core2.d: Likewise.
* gas/testsuite/gas/i386/nops-1-i386-i686.d: Likewise.
* gas/testsuite/gas/i386/nops-1-i386.d: Likewise.
* gas/testsuite/gas/i386/nops-1-i686.d: Likewise.
* gas/testsuite/gas/i386/nops-1-k8.d: Likewise.
* gas/testsuite/gas/i386/nops-1.d: Likewise.
* gas/testsuite/gas/i386/nops-2-core2.d: Likewise.
* gas/testsuite/gas/i386/nops-2-i386.d: Likewise.
* gas/testsuite/gas/i386/nops-2.d: Likewise.
* gas/testsuite/gas/i386/nops-3-i386.d: Likewise.
* gas/testsuite/gas/i386/nops-3-i686.d: Likewise.
* gas/testsuite/gas/i386/nops-3.d: Likewise.
* gas/testsuite/gas/i386/nops-4-i386.d: Likewise.
* gas/testsuite/gas/i386/nops-4-i686.d: Likewise.
* gas/testsuite/gas/i386/nops-4.d: Likewise.
* gas/testsuite/gas/i386/nops-4a-i686.d: Likewise.
* gas/testsuite/gas/i386/nops-5-i686.d: Likewise.
* gas/testsuite/gas/i386/nops-5.d: Likewise.
* gas/testsuite/gas/i386/nops-6.d: Likewise.
* gas/testsuite/gas/i386/nops16-1.d: Likewise.
* gas/testsuite/gas/i386/x86-64-nop-1.d: Likewise.
* gas/testsuite/gas/i386/x86-64-nop-2.d: Likewise.
* gas/testsuite/gas/i386/x86-64-nop-5.d: Likewise.
* gas/testsuite/gas/i386/x86-64-nops-1-core2.d: Likewise.
* gas/testsuite/gas/i386/x86-64-nops-1-g64.d: Likewise.
* gas/testsuite/gas/i386/x86-64-nops-1-k8.d: Likewise.
* gas/testsuite/gas/i386/x86-64-nops-1-pentium.d: Likewise.
* gas/testsuite/gas/i386/x86-64-nops-1.d: Likewise.
* gas/testsuite/gas/i386/x86-64-nops-2.d: Likewise.
* gas/testsuite/gas/i386/x86-64-nops-3.d: Likewise.
* gas/testsuite/gas/i386/x86-64-nops-4-core2.d: Likewise.
* gas/testsuite/gas/i386/x86-64-nops-4-k8.d: Likewise.
* gas/testsuite/gas/i386/x86-64-nops-4.d: Likewise.
* gas/testsuite/gas/i386/x86-64-nops-5-k8.d: Likewise.
* gas/testsuite/gas/i386/x86-64-nops-5.d: Likewise.
* gas/testsuite/gas/i386/ilp32/x86-64-nops-1-core2.d: Likewise.
* gas/testsuite/gas/i386/ilp32/x86-64-nops-1-k8.d: Likewise.
* gas/testsuite/gas/i386/ilp32/x86-64-nops-1-pentium.d: Likewise.
* gas/testsuite/gas/i386/ilp32/x86-64-nops-1.d: Likewise.
* gas/testsuite/gas/i386/ilp32/x86-64-nops-2.d: Likewise.
* gas/testsuite/gas/i386/ilp32/x86-64-nops-3.d: Likewise.
* gas/testsuite/gas/i386/ilp32/x86-64-nops-4-core2.d: Likewise.
* gas/testsuite/gas/i386/ilp32/x86-64-nops-4-k8.d: Likewise.
* gas/testsuite/gas/i386/ilp32/x86-64-nops-4.d: Likewise.
* gas/testsuite/gas/i386/ilp32/x86-64-nops-5-k8.d: Likewise.
* gas/testsuite/gas/i386/ilp32/x86-64-nops-5.d: Likewise.
* gas/testsuite/gas/i386/nops-7.d: New file.
* gas/testsuite/gas/i386/nops-7.s: Likewise.
* gas/testsuite/gas/i386/x86-64-nops-7.d: Likewise.
Diffstat (limited to 'gas/doc')
-rw-r--r-- | gas/doc/as.texinfo | 7 |
1 files changed, 4 insertions, 3 deletions
diff --git a/gas/doc/as.texinfo b/gas/doc/as.texinfo index f56515e..43286e9 100644 --- a/gas/doc/as.texinfo +++ b/gas/doc/as.texinfo @@ -6212,9 +6212,10 @@ zero. Note: For Intel 80386 and AMD x86-64 targets, @var{control} specifies the size limit of a no-op instruction. The valid values of @var{control} -are between 0 and 8 for 16-bit mode, between 0 and 10 for 32-bit mode, -between 0 and 11 for 64-bit mode. When 0 is used, the no-op instruction -size limit is set to the maximum supported size. +are between 0 and 4 in 16-bit mode, between 0 and 7 when tuning for +older processors in 32-bit mode, between 0 and 11 in 64-bit mode or when +tuning for newer processors in 32-bit mode. When 0 is used, the no-op +instruction size limit is set to the maximum supported size. @node Octa @section @code{.octa @var{bignums}} |