Patchwork [09/12] tcg-s390: Use risbgz for andi

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Submitter Richard Henderson
Date March 27, 2013, 6:52 p.m.
Message ID <1364410353-24728-10-git-send-email-rth@twiddle.net>
Download mbox | patch
Permalink /patch/231806/
State New
Headers show

Comments

Richard Henderson - March 27, 2013, 6:52 p.m.
This is immediately usable by the tlb lookup code.

Signed-off-by: Richard Henderson <rth@twiddle.net>
---
 tcg/s390/tcg-target.c | 58 ++++++++++++++++++++++++++++++++++++++++++++++-----
 1 file changed, 53 insertions(+), 5 deletions(-)
Paolo Bonzini - March 27, 2013, 7:03 p.m.
Il 27/03/2013 19:52, Richard Henderson ha scritto:
> This is immediately usable by the tlb lookup code.
> 
> Signed-off-by: Richard Henderson <rth@twiddle.net>
> ---
>  tcg/s390/tcg-target.c | 58 ++++++++++++++++++++++++++++++++++++++++++++++-----
>  1 file changed, 53 insertions(+), 5 deletions(-)
> 
> diff --git a/tcg/s390/tcg-target.c b/tcg/s390/tcg-target.c
> index 203cbb5..2bab245 100644
> --- a/tcg/s390/tcg-target.c
> +++ b/tcg/s390/tcg-target.c
> @@ -827,6 +827,15 @@ static void tcg_out_ld_abs(TCGContext *s, TCGType type, TCGReg dest, void *abs)
>      tcg_out_ld(s, type, dest, dest, addr & 0xffff);
>  }
>  
> +static inline void tcg_out_risbg(TCGContext *s, TCGReg dest, TCGReg src,
> +                                 int msb, int lsb, int ofs, int z)
> +{
> +    /* Format RIE-f */
> +    tcg_out16(s, (RIE_RISBG & 0xff00) | (dest << 4) | src);
> +    tcg_out16(s, (msb << 8) | (z << 7) | lsb);
> +    tcg_out16(s, (ofs << 8) | (RIE_RISBG & 0xff));
> +}
> +
>  static void tgen_ext8s(TCGContext *s, TCGType type, TCGReg dest, TCGReg src)
>  {
>      if (facilities & FACILITY_EXT_IMM) {
> @@ -940,6 +949,36 @@ static inline void tgen64_addi(TCGContext *s, TCGReg dest, int64_t val)
>  
>  }
>  
> +/* Accept bit patterns like these:
> +    0....01....1
> +    1....10....0
> +    1..10..01..1
> +    0..01..10..0
> +   Copied from gcc sources.  */
> +static inline bool risbg_mask(uint64_t c)
> +{
> +    uint64_t lsb;
> +    /* We don't change the number of transitions by inverting,
> +       so make sure we start with the LSB zero.  */
> +    if (c & 1) {
> +        c = ~c;
> +    }
> +    /* Reject all zeros or all ones.  */
> +    if (c == 0) {
> +        return false;
> +    }
> +    /* Find the first transition.  */
> +    lsb = c & -c;
> +    /* Invert to look for a second transition.  */
> +    c = ~c;
> +    /* Erase the first transition.  */
> +    c &= -lsb;
> +    /* Find the second transition, if any.  */
> +    lsb = c & -c;
> +    /* Match if all the bits are 1's, or if c is zero.  */
> +    return c == -lsb;
> +}
> +
>  static void tgen_andi(TCGContext *s, TCGType type, TCGReg dest, uint64_t val)
>  {
>      static const S390Opcode ni_insns[4] = {
> @@ -986,6 +1025,19 @@ static void tgen_andi(TCGContext *s, TCGType type, TCGReg dest, uint64_t val)
>              }
>          }
>      }
> +    if ((facilities & FACILITY_GEN_INST_EXT) && risbg_mask(val)) {
> +        int msb, lsb;
> +        if ((val & 0x8000000000000001ull) == 0x8000000000000001ull) {
> +            /* Achieve wraparound by swapping msb and lsb.  */
> +            msb = 63 - ctz64(~val);
> +            lsb = clz64(~val) + 1;
> +        } else {
> +            msb = clz64(val);
> +            lsb = 63 - ctz64(val);
> +        }
> +        tcg_out_risbg(s, dest, dest, msb, lsb, 0, 1);
> +        return;
> +    }
>  
>      /* Fall back to loading the constant.  */
>      tcg_out_movi(s, type, TCG_TMP0, val);
> @@ -1142,11 +1194,7 @@ static void tgen_deposit(TCGContext *s, TCGReg dest, TCGReg src,
>  {
>      int lsb = (63 - ofs);
>      int msb = lsb - (len - 1);
> -
> -    /* Format RIE-f */
> -    tcg_out16(s, (RIE_RISBG & 0xff00) | (dest << 4) | src);
> -    tcg_out16(s, (msb << 8) | lsb);
> -    tcg_out16(s, (ofs << 8) | (RIE_RISBG & 0xff));
> +    tcg_out_risbg(s, dest, src, msb, lsb, ofs, 0);
>  }
>  
>  static void tgen_gotoi(TCGContext *s, int cc, tcg_target_long dest)
> 

I wonder if PPC can use this too.

Paolo
Richard Henderson - March 27, 2013, 7:27 p.m.
On 03/27/2013 12:03 PM, Paolo Bonzini wrote:
> I wonder if PPC can use this too.

Yep, though it's more complicated for ppc64.


r~

Patch

diff --git a/tcg/s390/tcg-target.c b/tcg/s390/tcg-target.c
index 203cbb5..2bab245 100644
--- a/tcg/s390/tcg-target.c
+++ b/tcg/s390/tcg-target.c
@@ -827,6 +827,15 @@  static void tcg_out_ld_abs(TCGContext *s, TCGType type, TCGReg dest, void *abs)
     tcg_out_ld(s, type, dest, dest, addr & 0xffff);
 }
 
+static inline void tcg_out_risbg(TCGContext *s, TCGReg dest, TCGReg src,
+                                 int msb, int lsb, int ofs, int z)
+{
+    /* Format RIE-f */
+    tcg_out16(s, (RIE_RISBG & 0xff00) | (dest << 4) | src);
+    tcg_out16(s, (msb << 8) | (z << 7) | lsb);
+    tcg_out16(s, (ofs << 8) | (RIE_RISBG & 0xff));
+}
+
 static void tgen_ext8s(TCGContext *s, TCGType type, TCGReg dest, TCGReg src)
 {
     if (facilities & FACILITY_EXT_IMM) {
@@ -940,6 +949,36 @@  static inline void tgen64_addi(TCGContext *s, TCGReg dest, int64_t val)
 
 }
 
+/* Accept bit patterns like these:
+    0....01....1
+    1....10....0
+    1..10..01..1
+    0..01..10..0
+   Copied from gcc sources.  */
+static inline bool risbg_mask(uint64_t c)
+{
+    uint64_t lsb;
+    /* We don't change the number of transitions by inverting,
+       so make sure we start with the LSB zero.  */
+    if (c & 1) {
+        c = ~c;
+    }
+    /* Reject all zeros or all ones.  */
+    if (c == 0) {
+        return false;
+    }
+    /* Find the first transition.  */
+    lsb = c & -c;
+    /* Invert to look for a second transition.  */
+    c = ~c;
+    /* Erase the first transition.  */
+    c &= -lsb;
+    /* Find the second transition, if any.  */
+    lsb = c & -c;
+    /* Match if all the bits are 1's, or if c is zero.  */
+    return c == -lsb;
+}
+
 static void tgen_andi(TCGContext *s, TCGType type, TCGReg dest, uint64_t val)
 {
     static const S390Opcode ni_insns[4] = {
@@ -986,6 +1025,19 @@  static void tgen_andi(TCGContext *s, TCGType type, TCGReg dest, uint64_t val)
             }
         }
     }
+    if ((facilities & FACILITY_GEN_INST_EXT) && risbg_mask(val)) {
+        int msb, lsb;
+        if ((val & 0x8000000000000001ull) == 0x8000000000000001ull) {
+            /* Achieve wraparound by swapping msb and lsb.  */
+            msb = 63 - ctz64(~val);
+            lsb = clz64(~val) + 1;
+        } else {
+            msb = clz64(val);
+            lsb = 63 - ctz64(val);
+        }
+        tcg_out_risbg(s, dest, dest, msb, lsb, 0, 1);
+        return;
+    }
 
     /* Fall back to loading the constant.  */
     tcg_out_movi(s, type, TCG_TMP0, val);
@@ -1142,11 +1194,7 @@  static void tgen_deposit(TCGContext *s, TCGReg dest, TCGReg src,
 {
     int lsb = (63 - ofs);
     int msb = lsb - (len - 1);
-
-    /* Format RIE-f */
-    tcg_out16(s, (RIE_RISBG & 0xff00) | (dest << 4) | src);
-    tcg_out16(s, (msb << 8) | lsb);
-    tcg_out16(s, (ofs << 8) | (RIE_RISBG & 0xff));
+    tcg_out_risbg(s, dest, src, msb, lsb, ofs, 0);
 }
 
 static void tgen_gotoi(TCGContext *s, int cc, tcg_target_long dest)