opcodes/cgen: Rework calculation of shift when inserting fields

The calculation of the shift amount, used to insert fields into the
instruction buffer, is not correct when the following conditions are all
true:
  - CGEN_INT_INSN_P is defined, and true.
  - CGEN_INSN_LSB0_P is true
  - Total instruction length is greater than the length of a single
    instruction word (the instruction is made of multiple words)
  - The word offset is non-zero (the field is outside the first word)

When the above conditions are all true, the calculated shift fails to
take account of the total instruction length.

After this commit the calculation of the shift amount is split into two
parts, first we calculate the shift required to get to BIT0 of the word
in which the field lives, then we calculate the shift required to place
the field within the instruction word.

The change in this commit only effects the CGEN_INT_INSN_P defined true
case, but changes the code for both CGEN_INSN_LSB0_P true, and false.

In the case of CGEN_INSN_LSB0_P being false, the code used to say:

	shift = total_length - (word_offset + start + length);

Now it says:

	shift_to_word = total_length - (word_offset + word_length);
	shift_within_word = word_length - start - length;
	shift = shift_to_word + shift_within_word;

From which we can see that in all cases the computed shift value should
be unchanged.

In the case of CGEN_INSN_LSB0_P being true, the code used to say:

	shift = (word_offset + start + 1) - length;

Now it says:

	shift_to_word = total_length - (word_offset + word_length);
	shift_within_word = start + 1 - length;
	shift = shift_to_word + shift_within_word;

In the case where 'total_length == word_length' AND 'word_offset ==
0' (which indicates an instruction of a single word), we see that the
computed shift value will be unchanged.  However, when the total_length
and word_length are different, and the word_offset is non-zero then the
computed shift value will be different (and correct).

opcodes/ChangeLog:

	* cgen-ibld.in (insert_normal): Rework calculation of shift.
	* epiphany-ibld.c: Regenerate.
	* fr30-ibld.c: Regenerate.
	* frv-ibld.c: Regenerate.
	* ip2k-ibld.c: Regenerate.
	* iq2000-ibld.c: Regenerate.
	* lm32-ibld.c: Regenerate.
	* m32c-ibld.c: Regenerate.
	* m32r-ibld.c: Regenerate.
	* mep-ibld.c: Regenerate.
	* mt-ibld.c: Regenerate.
	* or1k-ibld.c: Regenerate.
	* xc16x-ibld.c: Regenerate.
	* xstormy16-ibld.c: Regenerate.

diff --git a/opcodes/ChangeLog b/opcodes/ChangeLog
index da140496355d90b4ee3de568c0cf2e32b653c274..83cbe6fd2e546bdf40a5d92e6dd7bb881527f3a3 100644 (file)
--- a/opcodes/ChangeLog
+++ b/opcodes/ChangeLog
@@ -1,3 +1,20 @@
+2016-02-02  Andrew Burgess  <andrew.burgess@embecosm.com>
+
+       * cgen-ibld.in (insert_normal): Rework calculation of shift.
+       * epiphany-ibld.c: Regenerate.
+       * fr30-ibld.c: Regenerate.
+       * frv-ibld.c: Regenerate.
+       * ip2k-ibld.c: Regenerate.
+       * iq2000-ibld.c: Regenerate.
+       * lm32-ibld.c: Regenerate.
+       * m32c-ibld.c: Regenerate.
+       * m32r-ibld.c: Regenerate.
+       * mep-ibld.c: Regenerate.
+       * mt-ibld.c: Regenerate.
+       * or1k-ibld.c: Regenerate.
+       * xc16x-ibld.c: Regenerate.
+       * xstormy16-ibld.c: Regenerate.
+
 2016-02-02  Andrew Burgess  <andrew.burgess@embecosm.com>
 
        * epiphany-dis.c: Regenerated from latest cpu files.

diff --git a/opcodes/cgen-ibld.in b/opcodes/cgen-ibld.in
index 4730ff4ff6c9ed184f89ff9bd0e25af5ca806c2f..cd6fffa5aee8c029454e51b9f4008d58fae0ae25 100644 (file)
--- a/opcodes/cgen-ibld.in
+++ b/opcodes/cgen-ibld.in
@@ -207,12 +207,19 @@ insert_normal (CGEN_CPU_DESC cd,
 #if CGEN_INT_INSN_P
 
   {
-    int shift;
+    int shift_within_word, shift_to_word, shift;
 
+    /* How to shift the value to BIT0 of the word.  */
+    shift_to_word = total_length - (word_offset + word_length);
+
+    /* How to shift the value to the field within the word.  */
     if (CGEN_INSN_LSB0_P)
-      shift = (word_offset + start + 1) - length;
+      shift_within_word = start + 1 - length;
     else
-      shift = total_length - (word_offset + start + length);
+      shift_within_word = word_length - start - length;
+
+    /* The total SHIFT, then mask in the value.  */
+    shift = shift_to_word + shift_within_word;
     *buffer = (*buffer & ~(mask << shift)) | ((value & mask) << shift);
   }
 

diff --git a/opcodes/epiphany-ibld.c b/opcodes/epiphany-ibld.c
index c412169f4af7e2107cb5e29157ab7620e794f472..f978d4682ffda995b2496654100d4e4db23a8d41 100644 (file)
--- a/opcodes/epiphany-ibld.c
+++ b/opcodes/epiphany-ibld.c
@@ -207,12 +207,19 @@ insert_normal (CGEN_CPU_DESC cd,
 #if CGEN_INT_INSN_P
 
   {
-    int shift;
+    int shift_within_word, shift_to_word, shift;
 
+    /* How to shift the value to BIT0 of the word.  */
+    shift_to_word = total_length - (word_offset + word_length);
+
+    /* How to shift the value to the field within the word.  */
     if (CGEN_INSN_LSB0_P)
-      shift = (word_offset + start + 1) - length;
+      shift_within_word = start + 1 - length;
     else
-      shift = total_length - (word_offset + start + length);
+      shift_within_word = word_length - start - length;
+
+    /* The total SHIFT, then mask in the value.  */
+    shift = shift_to_word + shift_within_word;
     *buffer = (*buffer & ~(mask << shift)) | ((value & mask) << shift);
   }
 

diff --git a/opcodes/fr30-ibld.c b/opcodes/fr30-ibld.c
index 12b17335ba86096ee67b69c3591772109bb95267..1293e73ba29c5563fe09bc48ab05377d296a8806 100644 (file)
--- a/opcodes/fr30-ibld.c
+++ b/opcodes/fr30-ibld.c
@@ -207,12 +207,19 @@ insert_normal (CGEN_CPU_DESC cd,
 #if CGEN_INT_INSN_P
 
   {
-    int shift;
+    int shift_within_word, shift_to_word, shift;
 
+    /* How to shift the value to BIT0 of the word.  */
+    shift_to_word = total_length - (word_offset + word_length);
+
+    /* How to shift the value to the field within the word.  */
     if (CGEN_INSN_LSB0_P)
-      shift = (word_offset + start + 1) - length;
+      shift_within_word = start + 1 - length;
     else
-      shift = total_length - (word_offset + start + length);
+      shift_within_word = word_length - start - length;
+
+    /* The total SHIFT, then mask in the value.  */
+    shift = shift_to_word + shift_within_word;
     *buffer = (*buffer & ~(mask << shift)) | ((value & mask) << shift);
   }
 

diff --git a/opcodes/frv-ibld.c b/opcodes/frv-ibld.c
index bbcec67b3e69805ed94713848e411fcb7ff9375a..dba36aa60420ba778ef5f657eddf54bd2574463f 100644 (file)
--- a/opcodes/frv-ibld.c
+++ b/opcodes/frv-ibld.c
@@ -207,12 +207,19 @@ insert_normal (CGEN_CPU_DESC cd,
 #if CGEN_INT_INSN_P
 
   {
-    int shift;
+    int shift_within_word, shift_to_word, shift;
 
+    /* How to shift the value to BIT0 of the word.  */
+    shift_to_word = total_length - (word_offset + word_length);
+
+    /* How to shift the value to the field within the word.  */
     if (CGEN_INSN_LSB0_P)
-      shift = (word_offset + start + 1) - length;
+      shift_within_word = start + 1 - length;
     else
-      shift = total_length - (word_offset + start + length);
+      shift_within_word = word_length - start - length;
+
+    /* The total SHIFT, then mask in the value.  */
+    shift = shift_to_word + shift_within_word;
     *buffer = (*buffer & ~(mask << shift)) | ((value & mask) << shift);
   }
 

diff --git a/opcodes/ip2k-ibld.c b/opcodes/ip2k-ibld.c
index a46e34d7be3dafce2ed018a606ffd92fdf2a695e..fa6a736b060d1a0a7caa34e7f2b582cd2c11ac14 100644 (file)
--- a/opcodes/ip2k-ibld.c
+++ b/opcodes/ip2k-ibld.c
@@ -207,12 +207,19 @@ insert_normal (CGEN_CPU_DESC cd,
 #if CGEN_INT_INSN_P
 
   {
-    int shift;
+    int shift_within_word, shift_to_word, shift;
 
+    /* How to shift the value to BIT0 of the word.  */
+    shift_to_word = total_length - (word_offset + word_length);
+
+    /* How to shift the value to the field within the word.  */
     if (CGEN_INSN_LSB0_P)
-      shift = (word_offset + start + 1) - length;
+      shift_within_word = start + 1 - length;
     else
-      shift = total_length - (word_offset + start + length);
+      shift_within_word = word_length - start - length;
+
+    /* The total SHIFT, then mask in the value.  */
+    shift = shift_to_word + shift_within_word;
     *buffer = (*buffer & ~(mask << shift)) | ((value & mask) << shift);
   }
 

diff --git a/opcodes/iq2000-ibld.c b/opcodes/iq2000-ibld.c
index 74aa4da16a9c4bfd12b25f7b070b7ed9a5bea118..96faa3847a073f32ef5132ad27e41aeaab0d540f 100644 (file)
--- a/opcodes/iq2000-ibld.c
+++ b/opcodes/iq2000-ibld.c
@@ -207,12 +207,19 @@ insert_normal (CGEN_CPU_DESC cd,
 #if CGEN_INT_INSN_P
 
   {
-    int shift;
+    int shift_within_word, shift_to_word, shift;
 
+    /* How to shift the value to BIT0 of the word.  */
+    shift_to_word = total_length - (word_offset + word_length);
+
+    /* How to shift the value to the field within the word.  */
     if (CGEN_INSN_LSB0_P)
-      shift = (word_offset + start + 1) - length;
+      shift_within_word = start + 1 - length;
     else
-      shift = total_length - (word_offset + start + length);
+      shift_within_word = word_length - start - length;
+
+    /* The total SHIFT, then mask in the value.  */
+    shift = shift_to_word + shift_within_word;
     *buffer = (*buffer & ~(mask << shift)) | ((value & mask) << shift);
   }
 

diff --git a/opcodes/lm32-ibld.c b/opcodes/lm32-ibld.c
index 6a923c7a2f034ccac28c56b3fa9f852f9c00a733..784acc02be43343e0c1b2243d1a519e876bf00d1 100644 (file)
--- a/opcodes/lm32-ibld.c
+++ b/opcodes/lm32-ibld.c
@@ -207,12 +207,19 @@ insert_normal (CGEN_CPU_DESC cd,
 #if CGEN_INT_INSN_P
 
   {
-    int shift;
+    int shift_within_word, shift_to_word, shift;
 
+    /* How to shift the value to BIT0 of the word.  */
+    shift_to_word = total_length - (word_offset + word_length);
+
+    /* How to shift the value to the field within the word.  */
     if (CGEN_INSN_LSB0_P)
-      shift = (word_offset + start + 1) - length;
+      shift_within_word = start + 1 - length;
     else
-      shift = total_length - (word_offset + start + length);
+      shift_within_word = word_length - start - length;
+
+    /* The total SHIFT, then mask in the value.  */
+    shift = shift_to_word + shift_within_word;
     *buffer = (*buffer & ~(mask << shift)) | ((value & mask) << shift);
   }
 

diff --git a/opcodes/m32c-ibld.c b/opcodes/m32c-ibld.c
index b93de263f62a68a67c25ca45e7e9ea5ccc0be2a9..7066bbf2ae035cd69ec26da9e1b591a79236a45e 100644 (file)
--- a/opcodes/m32c-ibld.c
+++ b/opcodes/m32c-ibld.c
@@ -207,12 +207,19 @@ insert_normal (CGEN_CPU_DESC cd,
 #if CGEN_INT_INSN_P
 
   {
-    int shift;
+    int shift_within_word, shift_to_word, shift;
 
+    /* How to shift the value to BIT0 of the word.  */
+    shift_to_word = total_length - (word_offset + word_length);
+
+    /* How to shift the value to the field within the word.  */
     if (CGEN_INSN_LSB0_P)
-      shift = (word_offset + start + 1) - length;
+      shift_within_word = start + 1 - length;
     else
-      shift = total_length - (word_offset + start + length);
+      shift_within_word = word_length - start - length;
+
+    /* The total SHIFT, then mask in the value.  */
+    shift = shift_to_word + shift_within_word;
     *buffer = (*buffer & ~(mask << shift)) | ((value & mask) << shift);
   }
 

diff --git a/opcodes/m32r-ibld.c b/opcodes/m32r-ibld.c
index a1bbcef8bcd8589b046e50db2bd2b6912e2fbe0a..2b9e93a90101a32eee0506582f2717c79b74a551 100644 (file)
--- a/opcodes/m32r-ibld.c
+++ b/opcodes/m32r-ibld.c
@@ -207,12 +207,19 @@ insert_normal (CGEN_CPU_DESC cd,
 #if CGEN_INT_INSN_P
 
   {
-    int shift;
+    int shift_within_word, shift_to_word, shift;
 
+    /* How to shift the value to BIT0 of the word.  */
+    shift_to_word = total_length - (word_offset + word_length);
+
+    /* How to shift the value to the field within the word.  */
     if (CGEN_INSN_LSB0_P)
-      shift = (word_offset + start + 1) - length;
+      shift_within_word = start + 1 - length;
     else
-      shift = total_length - (word_offset + start + length);
+      shift_within_word = word_length - start - length;
+
+    /* The total SHIFT, then mask in the value.  */
+    shift = shift_to_word + shift_within_word;
     *buffer = (*buffer & ~(mask << shift)) | ((value & mask) << shift);
   }
 

diff --git a/opcodes/mep-ibld.c b/opcodes/mep-ibld.c
index d1e33fa730f728241b6ef562fd06a9795597046e..0faf9481d9de4ce444cdff61ddf01d571ef0a1a5 100644 (file)
--- a/opcodes/mep-ibld.c
+++ b/opcodes/mep-ibld.c
@@ -207,12 +207,19 @@ insert_normal (CGEN_CPU_DESC cd,
 #if CGEN_INT_INSN_P
 
   {
-    int shift;
+    int shift_within_word, shift_to_word, shift;
 
+    /* How to shift the value to BIT0 of the word.  */
+    shift_to_word = total_length - (word_offset + word_length);
+
+    /* How to shift the value to the field within the word.  */
     if (CGEN_INSN_LSB0_P)
-      shift = (word_offset + start + 1) - length;
+      shift_within_word = start + 1 - length;
     else
-      shift = total_length - (word_offset + start + length);
+      shift_within_word = word_length - start - length;
+
+    /* The total SHIFT, then mask in the value.  */
+    shift = shift_to_word + shift_within_word;
     *buffer = (*buffer & ~(mask << shift)) | ((value & mask) << shift);
   }
 

diff --git a/opcodes/mt-ibld.c b/opcodes/mt-ibld.c
index ffc7910d6ee4e02b7f8572e6f966884445ff17ed..c678e996953e8c08645b901b0846489017df7fb0 100644 (file)
--- a/opcodes/mt-ibld.c
+++ b/opcodes/mt-ibld.c
@@ -207,12 +207,19 @@ insert_normal (CGEN_CPU_DESC cd,
 #if CGEN_INT_INSN_P
 
   {
-    int shift;
+    int shift_within_word, shift_to_word, shift;
 
+    /* How to shift the value to BIT0 of the word.  */
+    shift_to_word = total_length - (word_offset + word_length);
+
+    /* How to shift the value to the field within the word.  */
     if (CGEN_INSN_LSB0_P)
-      shift = (word_offset + start + 1) - length;
+      shift_within_word = start + 1 - length;
     else
-      shift = total_length - (word_offset + start + length);
+      shift_within_word = word_length - start - length;
+
+    /* The total SHIFT, then mask in the value.  */
+    shift = shift_to_word + shift_within_word;
     *buffer = (*buffer & ~(mask << shift)) | ((value & mask) << shift);
   }
 

diff --git a/opcodes/or1k-ibld.c b/opcodes/or1k-ibld.c
index 040bd00bacb9f19f636249bd949d307f6067f6e4..b934ce1b9fcd25796e1baf872025f9b2d566e74a 100644 (file)
--- a/opcodes/or1k-ibld.c
+++ b/opcodes/or1k-ibld.c
@@ -207,12 +207,19 @@ insert_normal (CGEN_CPU_DESC cd,
 #if CGEN_INT_INSN_P
 
   {
-    int shift;
+    int shift_within_word, shift_to_word, shift;
 
+    /* How to shift the value to BIT0 of the word.  */
+    shift_to_word = total_length - (word_offset + word_length);
+
+    /* How to shift the value to the field within the word.  */
     if (CGEN_INSN_LSB0_P)
-      shift = (word_offset + start + 1) - length;
+      shift_within_word = start + 1 - length;
     else
-      shift = total_length - (word_offset + start + length);
+      shift_within_word = word_length - start - length;
+
+    /* The total SHIFT, then mask in the value.  */
+    shift = shift_to_word + shift_within_word;
     *buffer = (*buffer & ~(mask << shift)) | ((value & mask) << shift);
   }
 

diff --git a/opcodes/xc16x-ibld.c b/opcodes/xc16x-ibld.c
index 3deb3b0241f59ec70a4f7edbbe9c4404d49c8667..43c7a160e2339f6ae69b2a911220dad10e4141ee 100644 (file)
--- a/opcodes/xc16x-ibld.c
+++ b/opcodes/xc16x-ibld.c
@@ -207,12 +207,19 @@ insert_normal (CGEN_CPU_DESC cd,
 #if CGEN_INT_INSN_P
 
   {
-    int shift;
+    int shift_within_word, shift_to_word, shift;
 
+    /* How to shift the value to BIT0 of the word.  */
+    shift_to_word = total_length - (word_offset + word_length);
+
+    /* How to shift the value to the field within the word.  */
     if (CGEN_INSN_LSB0_P)
-      shift = (word_offset + start + 1) - length;
+      shift_within_word = start + 1 - length;
     else
-      shift = total_length - (word_offset + start + length);
+      shift_within_word = word_length - start - length;
+
+    /* The total SHIFT, then mask in the value.  */
+    shift = shift_to_word + shift_within_word;
     *buffer = (*buffer & ~(mask << shift)) | ((value & mask) << shift);
   }
 

diff --git a/opcodes/xstormy16-ibld.c b/opcodes/xstormy16-ibld.c
index 4d963945c85a622eb69beff45a4697a08200593f..2d05229ba661bc6596f4289d6fcc5f6b88c382f3 100644 (file)
--- a/opcodes/xstormy16-ibld.c
+++ b/opcodes/xstormy16-ibld.c
@@ -207,12 +207,19 @@ insert_normal (CGEN_CPU_DESC cd,
 #if CGEN_INT_INSN_P
 
   {
-    int shift;
+    int shift_within_word, shift_to_word, shift;
 
+    /* How to shift the value to BIT0 of the word.  */
+    shift_to_word = total_length - (word_offset + word_length);
+
+    /* How to shift the value to the field within the word.  */
     if (CGEN_INSN_LSB0_P)
-      shift = (word_offset + start + 1) - length;
+      shift_within_word = start + 1 - length;
     else
-      shift = total_length - (word_offset + start + length);
+      shift_within_word = word_length - start - length;
+
+    /* The total SHIFT, then mask in the value.  */
+    shift = shift_to_word + shift_within_word;
     *buffer = (*buffer & ~(mask << shift)) | ((value & mask) << shift);
   }