From d3d50934a9101416c3106497d6ea9ce548760253 Mon Sep 17 00:00:00 2001 From: "H.J. Lu" Date: Thu, 8 Mar 2018 06:41:34 -0800 Subject: [PATCH 1/1] x86-64: Also optimize "clr reg64" "clr reg" is an alias of "xor reg, reg". We can encode "clr reg64" as "xor reg32, reg32". gas/ * config/tc-i386.c (optimize_encoding): Also encode "clr reg64" as "xor reg32, reg32". * testsuite/gas/i386/x86-64-optimize-1.s: Add "clr reg64" tests. * testsuite/gas/i386/x86-64-optimize-1.d: Updated. opcodes/ * i386-opc.tbl: Add Optimize to clr. * i386-tbl.h: Regenerated. --- gas/ChangeLog | 7 +++++++ gas/config/tc-i386.c | 19 ++++++++++++------- gas/testsuite/gas/i386/x86-64-optimize-1.d | 2 ++ gas/testsuite/gas/i386/x86-64-optimize-1.s | 2 ++ opcodes/ChangeLog | 5 +++++ opcodes/i386-opc.tbl | 2 +- opcodes/i386-tbl.h | 2 +- 7 files changed, 30 insertions(+), 9 deletions(-) diff --git a/gas/ChangeLog b/gas/ChangeLog index d9ea1a45ca..7c37f133e0 100644 --- a/gas/ChangeLog +++ b/gas/ChangeLog @@ -1,3 +1,10 @@ +2018-03-08 H.J. Lu + + * config/tc-i386.c (optimize_encoding): Also encode "clr reg64" + as "xor reg32, reg32". + * testsuite/gas/i386/x86-64-optimize-1.s: Add "clr reg64" tests. + * testsuite/gas/i386/x86-64-optimize-1.d: Updated. + 2018-03-08 H.J. Lu * NEWS: Mention -mold-gcc removal. diff --git a/gas/config/tc-i386.c b/gas/config/tc-i386.c index 53ac4b4f82..1c64d08ab2 100644 --- a/gas/config/tc-i386.c +++ b/gas/config/tc-i386.c @@ -3801,7 +3801,8 @@ optimize_encoding (void) } } else if (flag_code == CODE_64BIT - && ((i.reg_operands == 1 + && ((i.types[1].bitfield.qword + && i.reg_operands == 1 && i.imm_operands == 1 && i.op[0].imms->X_op == O_constant && ((i.tm.base_opcode == 0xb0 @@ -3816,12 +3817,16 @@ optimize_encoding (void) || ((i.tm.base_opcode == 0xf6 || i.tm.base_opcode == 0xc6) && i.tm.extension_opcode == 0x0))))) - || (i.reg_operands == 2 - && i.op[0].regs == i.op[1].regs - && ((i.tm.base_opcode == 0x30 - || i.tm.base_opcode == 0x28) - && i.tm.extension_opcode == None))) - && i.types[1].bitfield.qword) + || (i.types[0].bitfield.qword + && ((i.reg_operands == 2 + && i.op[0].regs == i.op[1].regs + && ((i.tm.base_opcode == 0x30 + || i.tm.base_opcode == 0x28) + && i.tm.extension_opcode == None)) + || (i.reg_operands == 1 + && i.operands == 1 + && i.tm.base_opcode == 0x30 + && i.tm.extension_opcode == None))))) { /* Optimize: -O: andq $imm31, %r64 -> andl $imm31, %r32 diff --git a/gas/testsuite/gas/i386/x86-64-optimize-1.d b/gas/testsuite/gas/i386/x86-64-optimize-1.d index 506d586063..f7fd1beeea 100644 --- a/gas/testsuite/gas/i386/x86-64-optimize-1.d +++ b/gas/testsuite/gas/i386/x86-64-optimize-1.d @@ -50,4 +50,6 @@ Disassembly of section .text: +[a-f0-9]+: b8 ff 03 00 00 mov \$0x3ff,%eax +[a-f0-9]+: 48 b8 00 00 00 00 01 00 00 00 movabs \$0x100000000,%rax +[a-f0-9]+: 48 b8 00 00 00 00 01 00 00 00 movabs \$0x100000000,%rax + +[a-f0-9]+: 31 c0 xor %eax,%eax + +[a-f0-9]+: 45 31 f6 xor %r14d,%r14d #pass diff --git a/gas/testsuite/gas/i386/x86-64-optimize-1.s b/gas/testsuite/gas/i386/x86-64-optimize-1.s index 2c6dc6d8ec..15d8cb05da 100644 --- a/gas/testsuite/gas/i386/x86-64-optimize-1.s +++ b/gas/testsuite/gas/i386/x86-64-optimize-1.s @@ -45,3 +45,5 @@ _start: movq $1023,%rax mov $0x100000000,%rax movq $0x100000000,%rax + clrq %rax + clrq %r14 diff --git a/opcodes/ChangeLog b/opcodes/ChangeLog index 55f8a144ed..333dd431b3 100644 --- a/opcodes/ChangeLog +++ b/opcodes/ChangeLog @@ -1,3 +1,8 @@ +2018-03-08 H.J. Lu + + * i386-opc.tbl: Add Optimize to clr. + * i386-tbl.h: Regenerated. + 2018-03-08 H.J. Lu * i386-gen.c (opcode_modifiers): Remove OldGcc. diff --git a/opcodes/i386-opc.tbl b/opcodes/i386-opc.tbl index a3080be252..82863790a7 100644 --- a/opcodes/i386-opc.tbl +++ b/opcodes/i386-opc.tbl @@ -205,7 +205,7 @@ xor, 2, 0x34, None, 1, 0, W|No_sSuf|No_ldSuf, { Imm8|Imm16|Imm32|Imm32S, Acc|Byt xor, 2, 0x80, 0x6, 1, 0, W|Modrm|No_sSuf|No_ldSuf|IsLockable|HLEPrefixOk, { Imm8|Imm16|Imm32|Imm32S, Reg8|Reg16|Reg32|Reg64|Byte|Word|Dword|Qword|Unspecified|BaseIndex } // clr with 1 operand is really xor with 2 operands. -clr, 1, 0x30, None, 1, 0, W|Modrm|No_sSuf|No_ldSuf|RegKludge, { Reg8|Reg16|Reg32|Reg64 } +clr, 1, 0x30, None, 1, 0, W|Modrm|No_sSuf|No_ldSuf|RegKludge|Optimize, { Reg8|Reg16|Reg32|Reg64 } adc, 2, 0x10, None, 1, 0, D|W|CheckRegSize|Modrm|No_sSuf|No_ldSuf|IsLockable|HLEPrefixOk, { Reg8|Reg16|Reg32|Reg64, Reg8|Reg16|Reg32|Reg64|Byte|Word|Dword|Qword|Unspecified|BaseIndex } adc, 2, 0x83, 0x2, 1, 0, Modrm|No_bSuf|No_sSuf|No_ldSuf|IsLockable|HLEPrefixOk, { Imm8S, Reg16|Reg32|Reg64|Word|Dword|Qword|Unspecified|BaseIndex } diff --git a/opcodes/i386-tbl.h b/opcodes/i386-tbl.h index 433f257516..06b8b96344 100644 --- a/opcodes/i386-tbl.h +++ b/opcodes/i386-tbl.h @@ -2115,7 +2115,7 @@ const insn_template i386_optab[] = 0, 0, 0, 0, 0, 0 } }, { 0, 1, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 1, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, - 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, + 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0 }, { { { 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 0, 1, 0, 0, 0, 0, 0, 0, -- 2.34.1