Correct ppc popcntb logic, implement popcntw and popcntd

qemu already includes support for the popcntb instruction introduced
in POWER5 (although it doesn't actually allow you to choose POWER5).

However, the logic is slightly incorrect: it will generate results
truncated to 32-bits when the CPU is in 32-bit mode.  This is not
normal for powerpc - generally arithmetic instructions on a 64-bit
powerpc cpu will generate full 64 bit results, it's just that only the
low 32 bits will be significant for condition codes.

This patch corrects this nit, which actually simplifies the code slightly.

In addition, this patch implements the popcntw and popcntd
instructions added in POWER7, in preparation for allowing POWER7 as an
emulated CPU.

Signed-off-by: David Gibson <dwg@au1.ibm.com>
Signed-off-by: Alexander Graf <agraf@suse.de>

diff --git a/target-ppc/cpu.h b/target-ppc/cpu.h
index f293f859762d22f7b748290e91404bc158837c46..37dde390a84a7e22b75384fff9b0d9edf83c236f 100644 (file)
--- a/target-ppc/cpu.h
+++ b/target-ppc/cpu.h
@@ -1505,6 +1505,8 @@ enum {
     PPC_DCRX           = 0x2000000000000000ULL,
     /* user-mode DCR access, implemented in PowerPC 460                      */
     PPC_DCRUX          = 0x4000000000000000ULL,
+    /* popcntw and popcntd instructions                                      */
+    PPC_POPCNTWD       = 0x8000000000000000ULL,
 };
 
 /*****************************************************************************/

diff --git a/target-ppc/helper.h b/target-ppc/helper.h
index 2b4744d33178ba1bf43009dafda6fe489e7b8028..7c02be9cfdc7c4e39d025611c74af7f2456770f5 100644 (file)
--- a/target-ppc/helper.h
+++ b/target-ppc/helper.h
@@ -38,10 +38,11 @@ DEF_HELPER_2(mulldo, i64, i64, i64)
 
 DEF_HELPER_FLAGS_1(cntlzw, TCG_CALL_CONST | TCG_CALL_PURE, tl, tl)
 DEF_HELPER_FLAGS_1(popcntb, TCG_CALL_CONST | TCG_CALL_PURE, tl, tl)
+DEF_HELPER_FLAGS_1(popcntw, TCG_CALL_CONST | TCG_CALL_PURE, tl, tl)
 DEF_HELPER_2(sraw, tl, tl, tl)
 #if defined(TARGET_PPC64)
 DEF_HELPER_FLAGS_1(cntlzd, TCG_CALL_CONST | TCG_CALL_PURE, tl, tl)
-DEF_HELPER_FLAGS_1(popcntb_64, TCG_CALL_CONST | TCG_CALL_PURE, tl, tl)
+DEF_HELPER_FLAGS_1(popcntd, TCG_CALL_CONST | TCG_CALL_PURE, tl, tl)
 DEF_HELPER_2(srad, tl, tl, tl)
 #endif
 

diff --git a/target-ppc/op_helper.c b/target-ppc/op_helper.c
index aa2e8ba415857edf973bfe22b27ed51b75a31068..b1b883d0a7bccbedf1256594e953d186d0eae028 100644 (file)
--- a/target-ppc/op_helper.c
+++ b/target-ppc/op_helper.c
@@ -499,6 +499,50 @@ target_ulong helper_srad (target_ulong value, target_ulong shift)
 }
 #endif
 
+#if defined(TARGET_PPC64)
+target_ulong helper_popcntb (target_ulong val)
+{
+    val = (val & 0x5555555555555555ULL) + ((val >>  1) &
+                                           0x5555555555555555ULL);
+    val = (val & 0x3333333333333333ULL) + ((val >>  2) &
+                                           0x3333333333333333ULL);
+    val = (val & 0x0f0f0f0f0f0f0f0fULL) + ((val >>  4) &
+                                           0x0f0f0f0f0f0f0f0fULL);
+    return val;
+}
+
+target_ulong helper_popcntw (target_ulong val)
+{
+    val = (val & 0x5555555555555555ULL) + ((val >>  1) &
+                                           0x5555555555555555ULL);
+    val = (val & 0x3333333333333333ULL) + ((val >>  2) &
+                                           0x3333333333333333ULL);
+    val = (val & 0x0f0f0f0f0f0f0f0fULL) + ((val >>  4) &
+                                           0x0f0f0f0f0f0f0f0fULL);
+    val = (val & 0x00ff00ff00ff00ffULL) + ((val >>  8) &
+                                           0x00ff00ff00ff00ffULL);
+    val = (val & 0x0000ffff0000ffffULL) + ((val >> 16) &
+                                           0x0000ffff0000ffffULL);
+    return val;
+}
+
+target_ulong helper_popcntd (target_ulong val)
+{
+    val = (val & 0x5555555555555555ULL) + ((val >>  1) &
+                                           0x5555555555555555ULL);
+    val = (val & 0x3333333333333333ULL) + ((val >>  2) &
+                                           0x3333333333333333ULL);
+    val = (val & 0x0f0f0f0f0f0f0f0fULL) + ((val >>  4) &
+                                           0x0f0f0f0f0f0f0f0fULL);
+    val = (val & 0x00ff00ff00ff00ffULL) + ((val >>  8) &
+                                           0x00ff00ff00ff00ffULL);
+    val = (val & 0x0000ffff0000ffffULL) + ((val >> 16) &
+                                           0x0000ffff0000ffffULL);
+    val = (val & 0x00000000ffffffffULL) + ((val >> 32) &
+                                           0x00000000ffffffffULL);
+    return val;
+}
+#else
 target_ulong helper_popcntb (target_ulong val)
 {
     val = (val & 0x55555555) + ((val >>  1) & 0x55555555);
@@ -507,12 +551,13 @@ target_ulong helper_popcntb (target_ulong val)
     return val;
 }
 
-#if defined(TARGET_PPC64)
-target_ulong helper_popcntb_64 (target_ulong val)
+target_ulong helper_popcntw (target_ulong val)
 {
-    val = (val & 0x5555555555555555ULL) + ((val >>  1) & 0x5555555555555555ULL);
-    val = (val & 0x3333333333333333ULL) + ((val >>  2) & 0x3333333333333333ULL);
-    val = (val & 0x0f0f0f0f0f0f0f0fULL) + ((val >>  4) & 0x0f0f0f0f0f0f0f0fULL);
+    val = (val & 0x55555555) + ((val >>  1) & 0x55555555);
+    val = (val & 0x33333333) + ((val >>  2) & 0x33333333);
+    val = (val & 0x0f0f0f0f) + ((val >>  4) & 0x0f0f0f0f);
+    val = (val & 0x00ff00ff) + ((val >>  8) & 0x00ff00ff);
+    val = (val & 0x0000ffff) + ((val >> 16) & 0x0000ffff);
     return val;
 }
 #endif

diff --git a/target-ppc/translate.c b/target-ppc/translate.c
index 425250832753a3d0637cdeb2037f2424677d2df1..88681359c788495d132452902dfa058706fee5a0 100644 (file)
--- a/target-ppc/translate.c
+++ b/target-ppc/translate.c
@@ -1483,13 +1483,21 @@ static void gen_xoris(DisasContext *ctx)
 /* popcntb : PowerPC 2.03 specification */
 static void gen_popcntb(DisasContext *ctx)
 {
+    gen_helper_popcntb(cpu_gpr[rA(ctx->opcode)], cpu_gpr[rS(ctx->opcode)]);
+}
+
+static void gen_popcntw(DisasContext *ctx)
+{
+    gen_helper_popcntw(cpu_gpr[rA(ctx->opcode)], cpu_gpr[rS(ctx->opcode)]);
+}
+
 #if defined(TARGET_PPC64)
-    if (ctx->sf_mode)
-        gen_helper_popcntb_64(cpu_gpr[rA(ctx->opcode)], cpu_gpr[rS(ctx->opcode)]);
-    else
-#endif
-        gen_helper_popcntb(cpu_gpr[rA(ctx->opcode)], cpu_gpr[rS(ctx->opcode)]);
+/* popcntd: PowerPC 2.06 specification */
+static void gen_popcntd(DisasContext *ctx)
+{
+    gen_helper_popcntd(cpu_gpr[rA(ctx->opcode)], cpu_gpr[rS(ctx->opcode)]);
 }
+#endif
 
 #if defined(TARGET_PPC64)
 /* extsw & extsw. */
@@ -8226,7 +8234,9 @@ GEN_HANDLER(oris, 0x19, 0xFF, 0xFF, 0x00000000, PPC_INTEGER),
 GEN_HANDLER(xori, 0x1A, 0xFF, 0xFF, 0x00000000, PPC_INTEGER),
 GEN_HANDLER(xoris, 0x1B, 0xFF, 0xFF, 0x00000000, PPC_INTEGER),
 GEN_HANDLER(popcntb, 0x1F, 0x03, 0x03, 0x0000F801, PPC_POPCNTB),
+GEN_HANDLER(popcntw, 0x1F, 0x1A, 0x0b, 0x0000F801, PPC_POPCNTWD),
 #if defined(TARGET_PPC64)
+GEN_HANDLER(popcntd, 0x1F, 0x1A, 0x0F, 0x0000F801, PPC_POPCNTWD),
 GEN_HANDLER(cntlzd, 0x1F, 0x1A, 0x01, 0x00000000, PPC_64B),
 #endif
 GEN_HANDLER(rlwimi, 0x14, 0xFF, 0xFF, 0x00000000, PPC_INTEGER),