[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [Xen-devel] [PATCH 3/6] x86emul: simplify FPU destination operand handling
Consolidate the copying of ea to dst: There's no need to set the type to OP_MEM, and instead the load cases setting it to OP_NONE allows the copying to be done just once per major opcode. Signed-off-by: Jan Beulich <jbeulich@xxxxxxxx> --- a/xen/arch/x86/x86_emulate/x86_emulate.c +++ b/xen/arch/x86/x86_emulate/x86_emulate.c @@ -3758,6 +3758,7 @@ x86_emulate( break; default: generate_exception_if(ea.type != OP_MEM, EXC_UD); + dst = ea; switch ( modrm_reg & 7 ) { case 0: /* fld m32fp */ @@ -3765,18 +3766,15 @@ x86_emulate( 4, ctxt)) != X86EMUL_OKAY ) goto done; emulate_fpu_insn_memsrc("flds", src.val); + dst.type = OP_NONE; break; case 2: /* fstp m32fp */ - ea.bytes = 4; - dst = ea; - dst.type = OP_MEM; emulate_fpu_insn_memdst("fsts", dst.val); + dst.bytes = 4; break; case 3: /* fstp m32fp */ - ea.bytes = 4; - dst = ea; - dst.type = OP_MEM; emulate_fpu_insn_memdst("fstps", dst.val); + dst.bytes = 4; break; case 4: /* fldenv - TODO */ goto cannot_emulate; @@ -3785,14 +3783,13 @@ x86_emulate( 2, ctxt)) != X86EMUL_OKAY ) goto done; emulate_fpu_insn_memsrc("fldcw", src.val); + dst.type = OP_NONE; break; case 6: /* fnstenv - TODO */ goto cannot_emulate; case 7: /* fnstcw m2byte */ - ea.bytes = 2; - dst = ea; - dst.type = OP_MEM; emulate_fpu_insn_memdst("fnstcw", dst.val); + dst.bytes = 2; break; default: generate_exception_if(true, EXC_UD); @@ -3872,6 +3869,7 @@ x86_emulate( break; default: generate_exception_if(ea.type != OP_MEM, EXC_UD); + dst = ea; switch ( modrm_reg & 7 ) { case 0: /* fild m32i */ @@ -3879,37 +3877,31 @@ x86_emulate( 4, ctxt)) != X86EMUL_OKAY ) goto done; emulate_fpu_insn_memsrc("fildl", src.val); + dst.type = OP_NONE; break; case 1: /* fisttp m32i */ host_and_vcpu_must_have(sse3); - ea.bytes = 4; - dst = ea; - dst.type = OP_MEM; emulate_fpu_insn_memdst("fisttpl", dst.val); + dst.bytes = 4; break; case 2: /* fist m32i */ - ea.bytes = 4; - dst = ea; - dst.type = OP_MEM; emulate_fpu_insn_memdst("fistl", dst.val); + dst.bytes = 4; break; case 3: /* fistp m32i */ - ea.bytes = 4; - dst = ea; - dst.type = OP_MEM; emulate_fpu_insn_memdst("fistpl", dst.val); + dst.bytes = 4; break; case 5: /* fld m80fp */ if ( (rc = ops->read(ea.mem.seg, ea.mem.off, &src.val, 10, ctxt)) != X86EMUL_OKAY ) goto done; emulate_fpu_insn_memsrc("fldt", src.val); + dst.type = OP_NONE; break; case 7: /* fstp m80fp */ - ea.bytes = 10; - dst.type = OP_MEM; - dst = ea; emulate_fpu_insn_memdst("fstpt", dst.val); + dst.bytes = 10; break; default: generate_exception_if(true, EXC_UD); @@ -3980,6 +3972,7 @@ x86_emulate( break; default: generate_exception_if(ea.type != OP_MEM, EXC_UD); + dst = ea; switch ( modrm_reg & 7 ) { case 0: /* fld m64fp */; @@ -3987,34 +3980,27 @@ x86_emulate( 8, ctxt)) != X86EMUL_OKAY ) goto done; emulate_fpu_insn_memsrc("fldl", src.val); + dst.type = OP_NONE; break; case 1: /* fisttp m64i */ host_and_vcpu_must_have(sse3); - ea.bytes = 8; - dst = ea; - dst.type = OP_MEM; emulate_fpu_insn_memdst("fisttpll", dst.val); + dst.bytes = 8; break; case 2: /* fst m64fp */ - ea.bytes = 8; - dst = ea; - dst.type = OP_MEM; emulate_fpu_insn_memdst("fstl", dst.val); + dst.bytes = 8; break; case 3: /* fstp m64fp */ - ea.bytes = 8; - dst = ea; - dst.type = OP_MEM; emulate_fpu_insn_memdst("fstpl", dst.val); + dst.bytes = 8; break; case 4: /* frstor - TODO */ case 6: /* fnsave - TODO */ goto cannot_emulate; case 7: /* fnstsw m2byte */ - ea.bytes = 2; - dst = ea; - dst.type = OP_MEM; emulate_fpu_insn_memdst("fnstsw", dst.val); + dst.bytes = 2; break; default: generate_exception_if(true, EXC_UD); @@ -4092,6 +4078,7 @@ x86_emulate( break; default: generate_exception_if(ea.type != OP_MEM, EXC_UD); + dst = ea; switch ( modrm_reg & 7 ) { case 0: /* fild m16i */ @@ -4099,49 +4086,42 @@ x86_emulate( 2, ctxt)) != X86EMUL_OKAY ) goto done; emulate_fpu_insn_memsrc("filds", src.val); + dst.type = OP_NONE; break; case 1: /* fisttp m16i */ host_and_vcpu_must_have(sse3); - ea.bytes = 2; - dst = ea; - dst.type = OP_MEM; emulate_fpu_insn_memdst("fisttps", dst.val); + dst.bytes = 2; break; case 2: /* fist m16i */ - ea.bytes = 2; - dst = ea; - dst.type = OP_MEM; emulate_fpu_insn_memdst("fists", dst.val); + dst.bytes = 2; break; case 3: /* fistp m16i */ - ea.bytes = 2; - dst = ea; - dst.type = OP_MEM; emulate_fpu_insn_memdst("fistps", dst.val); + dst.bytes = 2; break; case 4: /* fbld m80dec */ if ( (rc = ops->read(ea.mem.seg, ea.mem.off, &src.val, 10, ctxt)) != X86EMUL_OKAY ) goto done; emulate_fpu_insn_memsrc("fbld", src.val); + dst.type = OP_NONE; break; case 5: /* fild m64i */ if ( (rc = ops->read(ea.mem.seg, ea.mem.off, &src.val, 8, ctxt)) != X86EMUL_OKAY ) goto done; emulate_fpu_insn_memsrc("fildll", src.val); + dst.type = OP_NONE; break; case 6: /* fbstp packed bcd */ - ea.bytes = 10; - dst = ea; - dst.type = OP_MEM; emulate_fpu_insn_memdst("fbstp", dst.val); + dst.bytes = 10; break; case 7: /* fistp m64i */ - ea.bytes = 8; - dst = ea; - dst.type = OP_MEM; emulate_fpu_insn_memdst("fistpll", dst.val); + dst.bytes = 8; break; } } Attachment:
x86emul-FPU-simplify-dst.patch _______________________________________________ Xen-devel mailing list Xen-devel@xxxxxxxxxxxxx https://lists.xen.org/xen-devel
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