This patch fixes the register rename pass to allow for MEM that have "segment"
elements in the address.
rtl.h and rtanal.h allow MEM addresses to have the format "segment + base +
offset", where "segment" is an arbitrary UNSPEC. Without the patch, regrename
misidentifies the base and can break 64-bit addresses, on targets with 32-bit
registers, by placing the high-part in a non-contiguous register.
gcc/ChangeLog:
* regrename.cc (scan_rtx_address): Recurse for segment UNSPECs.
---
OK for mainline?
Andrew
gcc/regrename.cc | 6 ++++++
1 file changed, 6 insertions(+)
diff --git a/gcc/regrename.cc b/gcc/regrename.cc
index 1d36b90bdc5..7ffff3c3427 100644
--- a/gcc/regrename.cc
+++ b/gcc/regrename.cc
@@ -1341,6 +1341,12 @@ scan_rtx_address (rtx_insn *insn, rtx *loc, enum
reg_class cl,
rtx *locB = NULL;
enum rtx_code index_code = SCRATCH;
+ if (GET_CODE (op0) == UNSPEC)
+ {
+ /* We have a "segment" unspec; skip it. */
+ return scan_rtx_address (insn, &XEXP (x, 1), cl, action, mode, as);
+ }
+
if (GET_CODE (op0) == SUBREG)
{
op0 = SUBREG_REG (op0);
--
2.54.0
