MIPS: Add pattern insqisi_extended and inshisi_extended

This match pattern allows combination (zero_extract:DI 8, 24, QI)
with an sign-extend to 32bit INS instruction on TARGET_64BIT.

For SI mode, if the sign-bit is modified by bitops, we will need a
sign-extend operation.  Since 32bit INS instruction can be sure that
result is sign-extended, and the QImode src register is safe for INS, too.

(insn 19 18 20 2 (set (zero_extract:DI (reg/v:DI 200 [ val ])
            (const_int 8 [0x8])
            (const_int 24 [0x18]))
        (subreg:DI (reg:QI 205) 0)) "../xx.c":7:29 -1
     (nil))
(insn 20 19 23 2 (set (reg/v:DI 200 [ val ])
        (sign_extend:DI (subreg:SI (reg/v:DI 200 [ val ]) 0))) "../xx.c":7:29 -1
     (nil))

Combine try to merge them to:

(insn 20 19 23 2 (set (reg/v:DI 200 [ val ])
        (sign_extend:DI (ior:SI (and:SI (subreg:SI (reg/v:DI 200 [ val ]) 0)
                    (const_int 16777215 [0xffffff]))
                (ashift:SI (subreg:SI (reg:QI 205 [ MEM[(const unsigned char *)buf_8(D) + 3B] ]) 0)
                    (const_int 24 [0x18]))))) "../xx.c":7:29 18 {*insv_extended}
     (expr_list:REG_DEAD (reg:QI 205 [ MEM[(const unsigned char *)buf_8(D) + 3B] ])
        (nil)))

And do similarly for 16/16 pair:
(insn 13 12 14 2 (set (zero_extract:DI (reg/v:DI 198 [ val ])
            (const_int 16 [0x10])
            (const_int 16 [0x10]))
        (subreg:DI (reg:HI 201 [ MEM[(const short unsigned int *)buf_6(D) + 2B] ]) 0)) "xx.c":5:30 286 {*insvdi}
     (expr_list:REG_DEAD (reg:HI 201 [ MEM[(const short unsigned int *)buf_6(D) + 2B] ])
        (nil)))
(insn 14 13 17 2 (set (reg/v:DI 198 [ val ])
        (sign_extend:DI (subreg:SI (reg/v:DI 198 [ val ]) 0))) "xx.c":5:30 241 {extendsidi2}
     (nil))
------------>
(insn 14 13 17 2 (set (reg/v:DI 198 [ val ])
        (sign_extend:DI (ior:SI (ashift:SI (subreg:SI (reg:HI 201 [ MEM[(const short unsigned int *)buf_6(D) + 2B] ]) 0)
                    (const_int 16 [0x10]))
                (zero_extend:SI (subreg:HI (reg/v:DI 198 [ val ]) 0))))) "xx.c":5:30 284 {*inshisi_extended}
     (expr_list:REG_DEAD (reg:HI 201 [ MEM[(const short unsigned int *)buf_6(D) + 2B] ])
        (nil)))

Let's accept these patterns, and set the cost to 1 instruction.

gcc

	PR rtl-optimization/104914
	* config/mips/mips.md (insqisi_extended): New patterns.
	(inshisi_extended): Ditto.

gcc/testsuite

	* gcc.target/mips/pr104914.c: New test.

2 files changed, 49 insertions, 0 deletions

diff --git a/gcc/config/mips/mips.md b/gcc/config/mips/mips.md
index e1762ce..17dfcbd 100644
--- a/gcc/config/mips/mips.md
+++ b/gcc/config/mips/mips.md
@@ -4419,6 +4419,30 @@
   [(set_attr "type"     "arith")
    (set_attr "mode"     "SI")])
 
+(define_insn "*insqisi_extended"
+  [(set (match_operand:DI 0 "register_operand" "=d")
+    (sign_extend:DI
+      (ior:SI (and:SI (subreg:SI (match_dup 0) 0)
+		(const_int 16777215))
+	      (ashift:SI
+		(subreg:SI (match_operand:QI 1 "register_operand" "d") 0)
+		(const_int 24)))))]
+  "TARGET_64BIT && !TARGET_MIPS16 && ISA_HAS_EXT_INS"
+  "ins\t%0,%1,24,8"
+  [(set_attr "mode" "SI")
+   (set_attr "perf_ratio" "1")])
+
+(define_insn "*inshisi_extended"
+  [(set (match_operand:DI 0 "register_operand" "=d")
+    (sign_extend:DI
+      (ior:SI
+	(ashift:SI (subreg:SI (match_operand:HI 1 "register_operand" "d") 0)
+	  (const_int 16))
+	(zero_extend:SI (subreg:HI (match_dup 0) 0)))))]
+  "TARGET_64BIT && !TARGET_MIPS16 && ISA_HAS_EXT_INS"
+  "ins\t%0,%1,16,16"
+  [(set_attr "mode" "SI")
+   (set_attr "perf_ratio" "1")])
 
 (define_expand "insvmisalign<mode>"
   [(set (zero_extract:GPR (match_operand:BLK 0 "memory_operand")
diff --git a/gcc/testsuite/gcc.target/mips/pr104914.c b/gcc/testsuite/gcc.target/mips/pr104914.c
new file mode 100644
index 0000000..5dd10e8
--- /dev/null
+++ b/gcc/testsuite/gcc.target/mips/pr104914.c
@@ -0,0 +1,25 @@
+/* { dg-do run } */
+/* { dg-options "-mabi=64" } */
+
+extern void abort (void);
+extern void exit (int);
+
+NOMIPS16 int test (const unsigned char *buf)
+{
+  int val;
+  ((unsigned char*)&val)[0] = *buf++;
+  ((unsigned char*)&val)[1] = *buf++;
+  ((unsigned char*)&val)[2] = *buf++;
+  ((unsigned char*)&val)[3] = *buf++;
+  if(val > 0)
+    return 1;
+  else
+    return 0;
+}
+
+int main ()
+{
+  if (test("\xff\xff\xff\xff") != 0)
+    abort();
+  exit(0);
+}