MSP430: Use minimal code size library shift functions when optimizing for size

gcc/ChangeLog

2019-06-06  Jozef Lawrynowicz  <jozef.l@mittosystems.com>

	* config/msp430/msp430.md (ashlhi3): Use the const_variant of shift
	library functions only when not optimizing for size.
	(ashlsi3): Likewise.
	(ashrhi3): Likewise.
	(ashrsi3): Likewise.
	(lshrhi3): Likewise.
	(lshrsi3): Likewise.

gcc/testsuite/ChangeLog

2019-06-06  Jozef Lawrynowicz  <jozef.l@mittosystems.com>

	* gcc.target/msp430/size-optimized-shifts.c: New test.

From-SVN: r271997

gcc/ChangeLog

+2019-06-06  Jozef Lawrynowicz  <jozef.l@mittosystems.com>
+
+	* config/msp430/msp430.md (ashlhi3): Use the const_variant of shift
+	library functions only when not optimizing for size.
+	(ashlsi3): Likewise.
+	(ashrhi3): Likewise.
+	(ashrsi3): Likewise.
+	(lshrhi3): Likewise.
+	(lshrsi3): Likewise.
+
 2019-06-06  Andreas Krebbel  <krebbel@linux.ibm.com>
 
 	PR rtl-optimization/88751

gcc/config/msp430/msp430.md

@@ -769,7 +769,10 @@
 	     && INTVAL (operands[2]) == 1)
       emit_insn (gen_slli_1 (operands[0], operands[1]));
     else		 
-      msp430_expand_helper (operands, \"__mspabi_slli\", true);
+      /* The const variants of mspabi shifts have larger code size than the
+	 generic version, so use the generic version if optimizing for
+	 size.  */
+      msp430_expand_helper (operands, \"__mspabi_slli\", !optimize_size);
     DONE;
   }
 )
@@ -815,7 +818,7 @@
 	(ashift:SI (match_operand:SI 1 "general_operand")
 		   (match_operand:SI 2 "general_operand")))]
   ""
-  "msp430_expand_helper (operands, \"__mspabi_slll\", true);
+  "msp430_expand_helper (operands, \"__mspabi_slll\", !optimize_size);
    DONE;"
 )
 
@@ -842,7 +845,7 @@
 	     && INTVAL (operands[2]) == 1)
       emit_insn (gen_srai_1 (operands[0], operands[1]));
     else		 
-       msp430_expand_helper (operands, \"__mspabi_srai\", true);
+       msp430_expand_helper (operands, \"__mspabi_srai\", !optimize_size);
    DONE;
    }
 )
@@ -904,7 +907,7 @@
 	(ashiftrt:SI (match_operand:SI 1 "general_operand")
 		     (match_operand:SI 2 "general_operand")))]
   ""
-  "msp430_expand_helper (operands, \"__mspabi_sral\", true);
+  "msp430_expand_helper (operands, \"__mspabi_sral\", !optimize_size);
    DONE;"
 )
 
@@ -931,7 +934,7 @@
 	     && INTVAL (operands[2]) == 1)
       emit_insn (gen_srli_1 (operands[0], operands[1]));
     else		 
-      msp430_expand_helper (operands, \"__mspabi_srli\", true);
+      msp430_expand_helper (operands, \"__mspabi_srli\", !optimize_size);
     DONE;
   }
 )
@@ -983,7 +986,7 @@
 	(lshiftrt:SI (match_operand:SI 1 "general_operand")
 		     (match_operand:SI 2 "general_operand")))]
   ""
-  "msp430_expand_helper (operands, \"__mspabi_srll\", true);
+  "msp430_expand_helper (operands, \"__mspabi_srll\", !optimize_size);
    DONE;"
 )
 

gcc/testsuite/ChangeLog

 2019-06-06  Jozef Lawrynowicz  <jozef.l@mittosystems.com>
 
+	* gcc.target/msp430/size-optimized-shifts.c: New test.
+
+2019-06-06  Jozef Lawrynowicz  <jozef.l@mittosystems.com>
+
 	* gcc.target/msp430/emulate-slli.c: New test.
 	* gcc.target/msp430/emulate-srai.c: New test.
 	* gcc.target/msp430/emulate-srli.c: New test.

gcc/testsuite/gcc.target/msp430/size-optimized-shifts.c

+/* { dg-do compile } */
+/* { dg-options "-Os" } */
+/* { dg-final { scan-assembler-not "__mspabi_sral_4" } } */
+/* { dg-final { scan-assembler-not "__mspabi_srll_4" } } */
+/* { dg-final { scan-assembler-not "__mspabi_slll_4" } } */
+/* { dg-final { scan-assembler "__mspabi_sral" } } */
+/* { dg-final { scan-assembler "__mspabi_srll" } } */
+/* { dg-final { scan-assembler "__mspabi_slll" } } */
+
+/* Ensure that SImode shifts by a constant amount do not use the const_variant
+   of the shift library code when optimizing for size.  */
+
+long a;
+long b;
+long c;
+long d;
+unsigned long e;
+unsigned long f;
+
+void
+foo (void)
+{
+  a = b >> 4;
+  c = d << 4;
+  e = f >> 4;
+}