Patchwork [AArch64] Allow insv_imm to handle bigger immediates via masking to 16-bits

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Submitter Ian Bolton
Date May 17, 2013, 6:20 p.m.
Message ID <000001ce532b$2d14cc80$873e6580$@bolton@arm.com>
Download mbox | patch
Permalink /patch/244687/
State New
Headers show

Comments

Ian Bolton - May 17, 2013, 6:20 p.m.
The MOVK instruction is currently not used when operand 2 is
more than 16 bits, which leads to sub-optimal code.

This patch improves those situations by removing the check and
instead masking down to 16 bits within the new "X" format specifier
I added recently.

OK for trunk?

Cheers,
Ian


2013-05-17  Ian Bolton  <ian.bolton@arm.com>

	* config/aarch64/aarch64.c (aarch64_print_operand): Change the X
format
	specifier to only display bottom 16 bits.

	* config/aarch64/aarch64.md (insv_imm<mode>): Allow any-sized
immediate
	to match for operand 2, since it will be masked.

Patch

diff --git a/gcc/config/aarch64/aarch64.c b/gcc/config/aarch64/aarch64.c
index b57416c..1bdfd85 100644
--- a/gcc/config/aarch64/aarch64.c
+++ b/gcc/config/aarch64/aarch64.c
@@ -3424,13 +3424,13 @@  aarch64_print_operand (FILE *f, rtx x, char code)
       break;
 
     case 'X':
-      /* Print integer constant in hex.  */
+      /* Print bottom 16 bits of integer constant in hex.  */
       if (GET_CODE (x) != CONST_INT)
 	{
 	  output_operand_lossage ("invalid operand for '%%%c'", code);
 	  return;
 	}
-      asm_fprintf (f, "0x%wx", UINTVAL (x));
+      asm_fprintf (f, "0x%wx", UINTVAL (x) & 0xffff);
       break;
 
     case 'w':
diff --git a/gcc/config/aarch64/aarch64.md b/gcc/config/aarch64/aarch64.md
index b27bcda..403d717 100644
--- a/gcc/config/aarch64/aarch64.md
+++ b/gcc/config/aarch64/aarch64.md
@@ -858,9 +858,8 @@ 
 			  (const_int 16)
 			  (match_operand:GPI 1 "const_int_operand" "n"))
 	(match_operand:GPI 2 "const_int_operand" "n"))]
-  "INTVAL (operands[1]) < GET_MODE_BITSIZE (<MODE>mode)
-   && INTVAL (operands[1]) % 16 == 0
-   && UINTVAL (operands[2]) <= 0xffff"
+  "UINTVAL (operands[1]) < GET_MODE_BITSIZE (<MODE>mode)
+   && UINTVAL (operands[1]) % 16 == 0"
   "movk\\t%<w>0, %X2, lsl %1"
   [(set_attr "v8type" "movk")
    (set_attr "mode" "<MODE>")]