https://gcc.gnu.org/PR91269

From bebaf06774baca584c7e9f8410d0e49606a11d60 Mon Sep 17 00:00:00 2001
From: ebotcazou <ebotcazou@138bc75d-0d04-0410-961f-82ee72b054a4>
Date: Fri, 20 Sep 2019 09:42:40 +0000
Subject: [PATCH] 	PR target/91269 	* config/sparc/sparc.h
 (HARD_REGNO_CALLER_SAVE_MODE): Define.

git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@275994 138bc75d-0d04-0410-961f-82ee72b054a4
---
 gcc/config/sparc/sparc.h       |  7 ++++
 gcc/testsuite/gcc.dg/pr91269.c | 70 ++++++++++++++++++++++++++++++++++

--- a/gcc/config/sparc/sparc.h
+++ b/gcc/config/sparc/sparc.h
@@ -711,6 +711,13 @@ along with GCC; see the file COPYING3.  If not see
    register window instruction in the prologue.  */
 #define HARD_REGNO_RENAME_OK(FROM, TO) ((FROM) != 1)
 
+/* Select a register mode required for caller save of hard regno REGNO.
+   Contrary to what is documented, the default is not the smallest suitable
+   mode but the largest suitable mode for the given (REGNO, NREGS) pair and
+   it quickly creates paradoxical subregs that can be problematic.  */
+#define HARD_REGNO_CALLER_SAVE_MODE(REGNO, NREGS, MODE) \
+  ((MODE) == VOIDmode ? choose_hard_reg_mode (REGNO, NREGS, false) : (MODE))
+
 /* Specify the registers used for certain standard purposes.
    The values of these macros are register numbers.  */
 
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/pr91269.c
@@ -0,0 +1,70 @@
+/* PR target/91269 */
+/* Testcase by Sergei Trofimovich <slyfox@inbox.ru> */
+
+/* { dg-do assemble } */
+/* { dg-options "-O2 -Wno-int-conversion" }  */
+/* { dg-additional-options "-fcall-used-g6 -fPIE -mcpu=niagara4" { target sparc*-*-* } } */
+
+struct m;
+
+enum { a = 2 };
+int b[1];
+int d[2715];
+int e, f, h;
+enum { i = 2 } j;
+inline int c(int k) {
+  char *cp;
+  if (k >= 62 && k <= 247)
+    cp = b[k];
+  if (cp)
+    return 65533;
+  return 2;
+}
+inline int g(int k) {
+  if (k < sizeof(d))
+    return e;
+  return 0;
+}
+
+int u(struct m*, char*, char*);
+
+int l(struct m *k, char n, long o, int *p) {
+  int q, flags = j, r, s, lasttwo = *p;
+  char inptr, outptr;
+  while (inptr) {
+    if (__builtin_expect(h, 0))
+      break;
+    unsigned ch = inptr;
+    if (lasttwo) {
+      long need = lasttwo >> 3;
+      if (__builtin_expect(need > n, 0))
+        break;
+    } else if (s == i) {
+      long t = c(ch);
+      if (t != 65533) {
+        int jch = g(ch);
+        if (jch & 8)
+          continue;
+      }
+    }
+    if (ch <= 5)
+      ;
+    else {
+      long t = c(ch);
+      if (t != 65533)
+        ;
+      else {
+        switch (f >> 8)
+        case 79:
+          q = f == 20308 || f == 20350;
+        if (q)
+          if (j)
+            r = u(k, &inptr, &outptr);
+        s = *p;
+        if (r)
+          if (o && flags & a)
+            break;
+      }
+    }
+  }
+}
-- 
2.23.0