[PATCH, i386]: Fix PR78310, insn does not satisfy its constraints: {*bmi2_rorxdi3_1} with -mbmi2

[Uros Bizjak]

2016-11-11  Uros Bizjak  <ubiz...@gmail.com>

    PR target/78310
    * config/i386/i386.md (rotate to rotatex splitter): Avoid overflow
    when calculating operand 2.
    (rotate to rotatex zext splitter): Ditto.

testsuite/ChangeLog:

2016-11-11  Uros Bizjak  <ubiz...@gmail.com>

    PR target/78310
    * gcc.target/i386/pr78310.c: New test.

Bootstrapped and regression tested on x86_64-linux-gnu {,-m32}.

Committed to SVN, will be backported to release branches.

Uros.

Index: config/i386/i386.md
===================================================================
--- config/i386/i386.md (revision 242073)
+++ config/i386/i386.md (working copy)
@@ -10908,8 +10908,9 @@
   [(set (match_dup 0)
        (rotatert:SWI48 (match_dup 1) (match_dup 2)))]
 {
-  operands[2]
-    = GEN_INT (GET_MODE_BITSIZE (<MODE>mode) - INTVAL (operands[2]));
+  int bitsize = GET_MODE_BITSIZE (<MODE>mode);
+
+  operands[2] = GEN_INT ((bitsize - INTVAL (operands[2])) % bitsize);
 })
 
 (define_split
@@ -10975,8 +10976,9 @@
   [(set (match_dup 0)
        (zero_extend:DI (rotatert:SI (match_dup 1) (match_dup 2))))]
 {
-  operands[2]
-    = GEN_INT (GET_MODE_BITSIZE (SImode) - INTVAL (operands[2]));
+  int bitsize = GET_MODE_BITSIZE (SImode);
+
+  operands[2] = GEN_INT ((bitsize - INTVAL (operands[2])) % bitsize);
 })
 
 (define_split
Index: testsuite/gcc.target/i386/pr78310.c
===================================================================
--- testsuite/gcc.target/i386/pr78310.c (nonexistent)
+++ testsuite/gcc.target/i386/pr78310.c (working copy)
@@ -0,0 +1,15 @@
+/* { dg-do compile { target { ! ia32 } } } */
+/* { dg-options "-O -mbmi2" } */
+
+unsigned long long a;
+int b;
+
+int
+fn1(int p1)
+{
+  p1 &= 1;
+  p1 &= (short)~p1;
+  b = a;
+  a = a << p1 | a >> (64 - p1);
+  return p1 + 1 + a;
+}