From: Jan Beulich <jbeulich@suse.com>
To: Binutils <binutils@sourceware.org>
Cc: "H.J. Lu" <hjl.tools@gmail.com>, "Hu, Lin1" <lin1.hu@intel.com>
Subject: [PATCH] x86/APX: optimize MOVBE
Date: Fri, 12 Jan 2024 13:00:00 +0100 [thread overview]
Message-ID: <c04b9d63-5bea-44fa-95b2-ec5a40e997b7@suse.com> (raw)
With identical source and destination it can be covered by the NDD-to-
legacy conversion logic as well, even if in this case the original insn
doesn't use an NDD encoding. The size savings are even better here, for
the replacement (BSWAP) not having a ModR/M byte.
--- a/gas/config/tc-i386.c
+++ b/gas/config/tc-i386.c
@@ -7872,7 +7872,8 @@ match_template (char mnem_suffix)
&& t + 1 < current_templates.end
&& !t[1].opcode_modifier.evex
&& t[1].opcode_space <= SPACE_0F38
- && t->opcode_modifier.vexvvvv == VexVVVV_DST
+ && (t->opcode_modifier.vexvvvv == VexVVVV_DST
+ || t->mnem_off == MN_movbe)
&& (i.types[i.operands - 1].bitfield.dword
|| i.types[i.operands - 1].bitfield.qword))
{
--- a/gas/testsuite/gas/i386/x86-64-apx-ndd-optimize.d
+++ b/gas/testsuite/gas/i386/x86-64-apx-ndd-optimize.d
@@ -118,6 +118,9 @@ Disassembly of section .text:
\s*[a-f0-9]+:\s*67 0f 4d 90 90 90 90 90 cmovge -0x6f6f6f70\(%eax\),%edx
\s*[a-f0-9]+:\s*67 0f 4e 90 90 90 90 90 cmovle -0x6f6f6f70\(%eax\),%edx
\s*[a-f0-9]+:\s*67 0f 4f 90 90 90 90 90 cmovg -0x6f6f6f70\(%eax\),%edx
+\s*[a-f0-9]+:\s*62 f4 7d 08 60 c0 movbe %ax,%ax
+\s*[a-f0-9]+:\s*49 0f c8 bswap %r8
+\s*[a-f0-9]+:\s*d5 98 c8 bswap %r16
\s*[a-f0-9]+:\s*66 0f 38 f6 c3 adcx %ebx,%eax
\s*[a-f0-9]+:\s*66 0f 38 f6 c3 adcx %ebx,%eax
\s*[a-f0-9]+:\s*62 f4 fd 18 66 c3 adcx %rbx,%rax,%rax
--- a/gas/testsuite/gas/i386/x86-64-apx-ndd-optimize.s
+++ b/gas/testsuite/gas/i386/x86-64-apx-ndd-optimize.s
@@ -111,6 +111,9 @@ cmovl 0x90909090(%eax),%edx,%edx
cmovge 0x90909090(%eax),%edx,%edx
cmovle 0x90909090(%eax),%edx,%edx
cmovg 0x90909090(%eax),%edx,%edx
+movbe %ax,%ax
+movbe %r8,%r8
+movbe %r16,%r16
adcx %ebx,%eax,%eax
adcx %eax,%ebx,%eax
adcx %rbx,%rax,%rax
--- a/opcodes/i386-opc.tbl
+++ b/opcodes/i386-opc.tbl
@@ -210,6 +210,9 @@ mov, 0xf24, i386&No64, D|RegMem|IgnoreSi
// Move after swapping the bytes
movbe, 0x0f38f0, Movbe, D|Modrm|CheckOperandSize|No_bSuf|No_sSuf, { Word|Dword|Qword|Unspecified|BaseIndex, Reg16|Reg32|Reg64 }
movbe, 0x60, Movbe&APX_F, D|Modrm|CheckOperandSize|No_bSuf|No_sSuf|EVexMap4, { Reg16|Reg32|Reg64|Unspecified|BaseIndex, Reg16|Reg32|Reg64 }
+// This really is BSWAP, but wants "duplicating" here for easy EVEX -> REX2
+// conversion, restarting with the next sequential template.
+movbe, 0xfc8, Movbe&APX_F, No_bSuf|No_wSuf|No_sSuf, { Reg32|Reg64 }
// Move with sign extend.
movsb, 0xfbe, i386, Modrm|No_bSuf|No_sSuf, { Reg8|Unspecified|BaseIndex, Reg16|Reg32|Reg64 }
next reply other threads:[~2024-01-12 12:00 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-01-12 12:00 Jan Beulich [this message]
2024-01-12 12:28 ` Jan Beulich
2024-01-16 2:01 ` Hu, Lin1
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