From 51b91b19a390d390a5eaf25457c9bd82f699831a Mon Sep 17 00:00:00 2001
From: Julian Seward <jseward@acm.org>
Date: Fri, 23 Jul 2010 21:23:25 +0000
Subject: [PATCH] Support the SSE4 insn 'roundss' in 32-bit mode.  Lack of this
 was causing problems for people running 32-bit apps on MacOSX 10.6 on newer
 hardware.  Fixes #241377.

git-svn-id: svn://svn.valgrind.org/vex/trunk@1987
---
 VEX/priv/guest_x86_toIR.c | 61 +++++++++++++++++++++++++++++++++++++++
 VEX/priv/host_x86_isel.c  | 19 ++++++++++++
 2 files changed, 80 insertions(+)

diff --git a/VEX/priv/guest_x86_toIR.c b/VEX/priv/guest_x86_toIR.c
index 1dcdf627b3..2bf234a772 100644
--- a/VEX/priv/guest_x86_toIR.c
+++ b/VEX/priv/guest_x86_toIR.c
@@ -12522,6 +12522,67 @@ DisResult disInstr_X86_WRK (
    /* --- end of the SSSE3 decoder.                    --- */
    /* ---------------------------------------------------- */
 
+   /* ---------------------------------------------------- */
+   /* --- start of the SSE4 decoder                    --- */
+   /* ---------------------------------------------------- */
+
+   /* 66 0F 3A 0B /r ib = ROUNDSD imm8, xmm2/m64, xmm1
+      (Partial implementation only -- only deal with cases where
+      the rounding mode is specified directly by the immediate byte.)
+      66 0F 3A 0A /r ib = ROUNDSS imm8, xmm2/m32, xmm1
+      (Limitations ditto)
+   */
+   if (sz == 2 
+       && insn[0] == 0x0F && insn[1] == 0x3A
+       && (/*insn[2] == 0x0B || */insn[2] == 0x0A)) {
+
+      Bool   isD = insn[2] == 0x0B;
+      IRTemp src = newTemp(isD ? Ity_F64 : Ity_F32);
+      IRTemp res = newTemp(isD ? Ity_F64 : Ity_F32);
+      Int    imm = 0;
+
+      modrm = insn[3];
+
+      if (epartIsReg(modrm)) {
+         assign( src, 
+                 isD ? getXMMRegLane64F( eregOfRM(modrm), 0 )
+                     : getXMMRegLane32F( eregOfRM(modrm), 0 ) );
+         imm = insn[3+1];
+         if (imm & ~3) goto decode_failure;
+         delta += 3+1+1;
+         DIP( "rounds%c $%d,%s,%s\n",
+              isD ? 'd' : 's',
+              imm, nameXMMReg( eregOfRM(modrm) ),
+                   nameXMMReg( gregOfRM(modrm) ) );
+      } else {
+         addr = disAMode( &alen, sorb, delta+3, dis_buf );
+         assign( src, loadLE( isD ? Ity_F64 : Ity_F32, mkexpr(addr) ));
+         imm = insn[3+alen];
+         if (imm & ~3) goto decode_failure;
+         delta += 3+alen+1;
+         DIP( "roundsd $%d,%s,%s\n",
+              imm, dis_buf, nameXMMReg( gregOfRM(modrm) ) );
+      }
+
+      /* (imm & 3) contains an Intel-encoded rounding mode.  Because
+         that encoding is the same as the encoding for IRRoundingMode,
+         we can use that value directly in the IR as a rounding
+         mode. */
+      assign(res, binop(isD ? Iop_RoundF64toInt : Iop_RoundF32toInt,
+                  mkU32(imm & 3), mkexpr(src)) );
+
+      if (isD)
+         putXMMRegLane64F( gregOfRM(modrm), 0, mkexpr(res) );
+      else
+         putXMMRegLane32F( gregOfRM(modrm), 0, mkexpr(res) );
+
+      goto decode_success;
+   }
+
+   /* ---------------------------------------------------- */
+   /* --- end of the SSE4 decoder                      --- */
+   /* ---------------------------------------------------- */
+
    after_sse_decoders:
 
    /* ---------------------------------------------------- */
diff --git a/VEX/priv/host_x86_isel.c b/VEX/priv/host_x86_isel.c
index 02d83d8af8..e1242d69b6 100644
--- a/VEX/priv/host_x86_isel.c
+++ b/VEX/priv/host_x86_isel.c
@@ -2776,6 +2776,25 @@ static HReg iselFltExpr_wrk ( ISelEnv* env, IRExpr* e )
       return dst;
    }
 
+   if (e->tag == Iex_Binop && e->Iex.Binop.op == Iop_RoundF32toInt) {
+      HReg rf  = iselFltExpr(env, e->Iex.Binop.arg2);
+      HReg dst = newVRegF(env);
+
+      /* rf now holds the value to be rounded.  The first thing to do
+         is set the FPU's rounding mode accordingly. */
+
+      /* Set host rounding mode */
+      set_FPU_rounding_mode( env, e->Iex.Binop.arg1 );
+
+      /* grndint %rf, %dst */
+      addInstr(env, X86Instr_FpUnary(Xfp_ROUND, rf, dst));
+
+      /* Restore default FPU rounding. */
+      set_FPU_rounding_default( env );
+
+      return dst;
+   }
+
    ppIRExpr(e);
    vpanic("iselFltExpr_wrk");
 }
-- 
2.47.3