From: Gabe Black <gblack@eecs.umich.edu>
Date: Tue, 24 Jul 2007 22:37:16 +0000 (-0700)
Subject: Add a special case for "test" which needs an immediate even though everything else... 
X-Git-Tag: m5_2.0_beta4~282
X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=4bb1c5ba0c79b72b20b2ac9e196670011809819f;p=gem5.git

Add a special case for "test" which needs an immediate even though everything else with it's opcode doesn't.
Also made some spacing consistent.

--HG--
extra : convert_revision : 72a317f29c11705782e19840bef24354214d3143
---

diff --git a/src/arch/x86/predecoder.cc b/src/arch/x86/predecoder.cc
index 295ca10a4..7f8bc7abc 100644
--- a/src/arch/x86/predecoder.cc
+++ b/src/arch/x86/predecoder.cc
@@ -311,9 +311,19 @@ namespace X86ISA
             else
                 displacementSize = 0;
         }
+
+        // The "test" instruction in group 3 needs an immediate, even though
+        // the other instructions with the same actual opcode don't.
+        if (emi.opcode.num == 1 && (modRM.reg & 0x6) == 0) {
+           if (emi.opcode.op == 0xF6)
+               immediateSize = 1;
+           else if (emi.opcode.op == 0xF7)
+               immediateSize = (emi.opSize == 8) ? 4 : emi.opSize;
+        }
+
         //If there's an SIB, get that next.
         //There is no SIB in 16 bit mode.
-        if(modRM.rm == 4 && modRM.mod != 3) {
+        if (modRM.rm == 4 && modRM.mod != 3) {
                 // && in 32/64 bit mode)
             nextState = SIBState;
         } else if(displacementSize) {
@@ -339,9 +349,9 @@ namespace X86ISA
         emi.sib = nextByte;
         DPRINTF(Predecoder, "Found SIB byte %#x.\n", nextByte);
         consumeByte();
-        if(emi.modRM.mod == 0 && emi.sib.base == 5)
+        if (emi.modRM.mod == 0 && emi.sib.base == 5)
             displacementSize = 4;
-        if(displacementSize) {
+        if (displacementSize) {
             nextState = DisplacementState;
         } else if(immediateSize) {
             nextState = ImmediateState;