MSP430: Dont add offsets to addresses when emitting asm for post_inc

Some insns, which operate on SImode operands, output assembler template
that comprise of multiple instructions using HImode operands. To access
the high word of an SImode operand, an operand selector '%H' is used to
offset the operand value by a constant amount.

When one of these HImode operands is a memory reference to a post_inc,
the address does not need to be offset, since the preceding instruction
has already offset the address to the correct value.

This fixes an ICE in change_address_1, at emit-rtl.c:2318 for
gcc.c-torture/execute/pr20527-1.c in the "-mlarge -O2 -flto
-fuse-linker-plugin -fno-fat-lto-objects" configuration.

This test generated the following insn, and the attempt to output the
high part of the post_inc address caused the ICE.
(set (reg:SI 6 R6)
     (minus:SI (reg:SI 6 R6)
               (mem:SI (post_inc:PSI (reg:PSI 10 R10)) {subsi3}

gcc/ChangeLog:

2020-04-13  Jozef Lawrynowicz  <jozef.l@mittosystems.com>

	* config/msp430/msp430.c (msp430_print_operand): Don't add offsets to
	memory references in %B, %C and %D operand selectors when the inner
	operand is a post increment address.

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index c0ac32dccf6e11c7994d08272ddd509f492bfdc3..8bfc2127989bd01447523c6004b8b8ce193bd86e 100644 (file)
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,9 @@
+2020-04-13  Jozef Lawrynowicz  <jozef.l@mittosystems.com>
+
+       * config/msp430/msp430.c (msp430_print_operand): Don't add offsets to
+       memory references in %B, %C and %D operand selectors when the inner
+       operand is a post increment address.
+
 2020-04-13  Jozef Lawrynowicz  <jozef.l@mittosystems.com>
 
        * config/msp430/msp430.c (msp430_print_operand): Offset a %C memory

diff --git a/gcc/config/msp430/msp430.c b/gcc/config/msp430/msp430.c
index 96532740ac15b031a1e42799f0b67396f1be83c0..e77ca101599d9ed704575dcdb90eefa8b808b5c2 100644 (file)
--- a/gcc/config/msp430/msp430.c
+++ b/gcc/config/msp430/msp430.c
@@ -3474,7 +3474,9 @@ msp430_print_operand (FILE * file, rtx op, int letter)
       switch (GET_CODE (op))
        {
        case MEM:
-         op = adjust_address (op, Pmode, 2);
+         /* We don't need to adjust the address for post_inc.  */
+         op = adjust_address (op, Pmode,
+                              (GET_CODE (XEXP (op, 0)) == POST_INC) ? 0 : 2);
          break;
        case REG:
          op = gen_rtx_REG (Pmode, REGNO (op) + 1);
@@ -3492,7 +3494,8 @@ msp430_print_operand (FILE * file, rtx op, int letter)
       switch (GET_CODE (op))
        {
        case MEM:
-         op = adjust_address (op, Pmode, 4);
+         op = adjust_address (op, Pmode,
+                              (GET_CODE (XEXP (op, 0)) == POST_INC) ? 0 : 4);
          break;
        case REG:
          op = gen_rtx_REG (Pmode, REGNO (op) + 2);
@@ -3510,7 +3513,8 @@ msp430_print_operand (FILE * file, rtx op, int letter)
       switch (GET_CODE (op))
        {
        case MEM:
-         op = adjust_address (op, Pmode, 6);
+         op = adjust_address (op, Pmode,
+                              (GET_CODE (XEXP (op, 0)) == POST_INC) ? 0 : 6);
          break;
        case REG:
          op = gen_rtx_REG (Pmode, REGNO (op) + 3);