openwrt-owl/toolchain/gcc/patches/4.4.7/931-avr32_disable_shifted_d...

33 lines
835 B
Diff

--- a/gcc/config/avr32/avr32.c
+++ b/gcc/config/avr32/avr32.c
@@ -6726,7 +6726,28 @@ avr32_reorg_optimization (void)
}
}
- if (TARGET_MD_REORG_OPTIMIZATION && (optimize_size || (optimize > 0)))
+ /* Disabled this optimization since it has a bug */
+ /* In the case where the data instruction the shifted insn gets folded
+ * into is a branch destination, this breaks, i.e.
+ *
+ * add r8, r10, r8 << 2
+ * 1:
+ * ld.w r11, r8[0]
+ * ...
+ * mov r8, sp
+ * rjmp 1b
+ *
+ * gets folded to:
+ *
+ * 1:
+ * ld.w r11, r10[r8 << 2]
+ * ...
+ * mov r8, sp
+ * rjmp 1b
+ *
+ * which is clearly wrong..
+ */
+ if (0 && TARGET_MD_REORG_OPTIMIZATION && (optimize_size || (optimize > 0)))
{
/* Scan through all insns looking for shifted add operations */