https://gcc.gnu.org/g:f3d9c120a1959c5b094001516c1e5cb4ba6f4080
commit r14-10597-gf3d9c120a1959c5b094001516c1e5cb4ba6f4080
Author: Georg-Johann Lay <a...@gjlay.de>
Date: Sat Aug 17 12:49:42 2024 +0200
AVR: target/116390 - Fix an avrtiny asm out template.
PR target/116390
gcc/
* config/avr/avr.cc (avr_out_movsi_mr_r_reg_disp_tiny): Fix
output templates for the reg_base == reg_src and
reg_src == reg_base - 2 cases.
gcc/testsuite/
* gcc.target/avr/torture/pr116390.c: New test.
(cherry picked from commit 4065d163151b07b274241377e71dad028576db88)
Diff:
---
gcc/config/avr/avr.cc | 30 +++++------
gcc/testsuite/gcc.target/avr/torture/pr116390.c | 71 +++++++++++++++++++++++++
2 files changed, 86 insertions(+), 15 deletions(-)
diff --git a/gcc/config/avr/avr.cc b/gcc/config/avr/avr.cc
index 71929b28160..3c1a0bf707f 100644
--- a/gcc/config/avr/avr.cc
+++ b/gcc/config/avr/avr.cc
@@ -5501,33 +5501,33 @@ avr_out_movsi_mr_r_reg_disp_tiny (rtx op[], int *l)
rtx src = op[1];
rtx base = XEXP (dest, 0);
int reg_base = REGNO (XEXP (base, 0));
- int reg_src =true_regnum (src);
+ int reg_src = true_regnum (src);
if (reg_base == reg_src)
{
*l = 11;
- return ("mov __tmp_reg__,%A2" CR_TAB
- "mov __zero_reg__,%B2" CR_TAB
+ return ("mov __tmp_reg__,%A1" CR_TAB
+ "mov __zero_reg__,%B1" CR_TAB
TINY_ADIW (%I0, %J0, %o0) CR_TAB
"st %b0+,__tmp_reg__" CR_TAB
"st %b0+,__zero_reg__" CR_TAB
- "st %b0+,%C2" CR_TAB
- "st %b0,%D2" CR_TAB
+ "st %b0+,%C1" CR_TAB
+ "st %b0,%D1" CR_TAB
"clr __zero_reg__" CR_TAB
TINY_SBIW (%I0, %J0, %o0+3));
}
else if (reg_src == reg_base - 2)
{
- *l = 11;
- return ("mov __tmp_reg__,%C2" CR_TAB
- "mov __zero_reg__,%D2" CR_TAB
- TINY_ADIW (%I0, %J0, %o0) CR_TAB
- "st %b0+,%A0" CR_TAB
- "st %b0+,%B0" CR_TAB
- "st %b0+,__tmp_reg__" CR_TAB
- "st %b0,__zero_reg__" CR_TAB
- "clr __zero_reg__" CR_TAB
- TINY_SBIW (%I0, %J0, %o0+3));
+ // This awkward case can occur when ext-dce turns zero-extend:SI(HI)
+ // into a paradoxical subreg, which register allocation may turn into
+ // something like *(R28:HI + 7) = R26:SI. There is actually no need
+ // to store the upper 2 bytes of R26:SI as they are unused rubbish.
+ // See PR116390.
+ *l = 6;
+ return (TINY_ADIW (%I0, %J0, %o0) CR_TAB
+ "st %b0+,%A1" CR_TAB
+ "st %b0,%B1" CR_TAB
+ TINY_SBIW (%I0, %J0, %o0+1));
}
*l = 8;
return (TINY_ADIW (%I0, %J0, %o0) CR_TAB
diff --git a/gcc/testsuite/gcc.target/avr/torture/pr116390.c
b/gcc/testsuite/gcc.target/avr/torture/pr116390.c
new file mode 100644
index 00000000000..70c1ad62936
--- /dev/null
+++ b/gcc/testsuite/gcc.target/avr/torture/pr116390.c
@@ -0,0 +1,71 @@
+/* { dg-do compile } */
+/* { dg-additional-options "-std=c99" } */
+
+typedef struct
+{
+ int i;
+} MyStruct;
+
+void f_ic (int, char);
+void f_pi (char const *, int);
+void f_iic (int, int, char);
+
+const MyStruct *f_rms (void);
+
+char *f_rcp (void);
+int f_ri (void);
+
+void badFoo (void)
+{
+ const MyStruct* ps = f_rms ();
+ const char* pc = f_rcp ();
+
+ unsigned n1 = f_rcp () - pc;
+
+ if (n1)
+ {
+ long n2 = n1 - ps->i;
+ if (n2 > 0)
+ {
+ if (f_ri ())
+ n2 = n1;
+
+ if (f_ri ())
+ {
+ f_iic (1, 2 * n2, ' ');
+ }
+ else
+ f_pi (pc, n2);
+ }
+ if (ps->i > 0)
+ {
+ if (n2 >= 0)
+ f_pi (pc + n2, ps->i);
+ else
+ {
+ f_ic (n2, ' ');
+ }
+ }
+
+ const int which = f_ri ();
+ switch (which)
+ {
+ case 1:
+ if (f_ri ())
+ f_rcp ()[1] = ' ';
+ break;
+
+ case 2:
+ f_pi (f_rcp (), 1);
+ break;
+
+ case 3:
+ if (f_ri () && n1 < 0)
+ f_ic (n1, ' ');
+ else
+ f_rcp ()[1] = ' ';
+ break;
+
+ }
+ }
+}
