[PR104447] LRA: Do not split non-alloc hard regs.

LRA tried to split non-allocated hard reg for reload pseudos again and
again until number of assignment passes reaches the limit.  The patch fixes
this.

gcc/ChangeLog:

	PR rtl-optimization/104447
	* lra-constraints.cc (spill_hard_reg_in_range): Initiate ignore
	hard reg set by lra_no_alloc_regs.

gcc/testsuite/ChangeLog:

	PR rtl-optimization/104447
	* gcc.target/i386/pr104447.c: New.

diff --git a/gcc/lra-constraints.cc b/gcc/lra-constraints.cc
index c700c3f..b2c4590 100644 (file)
--- a/gcc/lra-constraints.cc
+++ b/gcc/lra-constraints.cc
@@ -6008,7 +6008,7 @@ spill_hard_reg_in_range (int regno, enum reg_class rclass, rtx_insn *from, rtx_i
   HARD_REG_SET ignore;
   
   lra_assert (from != NULL && to != NULL);
-  CLEAR_HARD_REG_SET (ignore);
+  ignore = lra_no_alloc_regs;
   EXECUTE_IF_SET_IN_BITMAP (&lra_reg_info[regno].insn_bitmap, 0, uid, bi)
     {
       lra_insn_recog_data_t id = lra_insn_recog_data[uid];

diff --git a/gcc/testsuite/gcc.target/i386/pr104447.c b/gcc/testsuite/gcc.target/i386/pr104447.c
new file mode 100644 (file)
index 0000000..bf11e86
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/pr104447.c
@@ -0,0 +1,14 @@
+/* { dg-do compile } */
+/* { dg-options "-O2 -pg" } */
+
+int
+bar (int x)
+{
+  asm goto ("" : : "r" (x), "r" (x + 1), "r" (x + 2), "r" (x + 3), /* { dg-error "operand has impossible constraints" } */
+           "r" (x + 4), "r" (x + 5), "r" (x + 6), "r" (x + 7),
+           "r" (x + 8), "r" (x + 9), "r" (x + 10), "r" (x + 11),
+           "r" (x + 12), "r" (x + 13), "r" (x + 14), "r" (x + 15),
+           "r" (x + 16) : : lab);
+ lab:
+  return 0;
+}