Hi,
Backporting of the fix went into GCC 5 seems to intrusive for the
released branches. Hence I'd propose to remove the problematic patterns
altogether, as they can silently generate wrong code. The attached
patch does that. Tested briefly with 'make all' and with
make -k check-gcc RUNTESTFLAGS="sh.exp --target_board=sh-sim
\{-m2/-ml,-m2/-mb,-m2a/-mb,-m4/-ml,-m4/-mb,-m4a/-ml,-m4a/-mb}"
Kaz, do you have any objections?
Cheers,
Oleg
gcc/ChangeLog:
PR target/53988
* config/sh/sh.md (*tst<mode>_t_zero): Remove insns.
gcc/testsuite/ChangeLog:
PR target/53988
* gcc.target/sh/pr53988.c: Mark tests as xfail.
Index: gcc/config/sh/sh.md
===================================================================
--- gcc/config/sh/sh.md (revision 221258)
+++ gcc/config/sh/sh.md (working copy)
@@ -651,32 +651,6 @@
"tst #255,%0"
[(set_attr "type" "mt_group")])
-;; This pattern might be risky because it also tests the upper bits and not
-;; only the subreg. However, it seems that combine will get to this only
-;; when testing sign/zero extended values. In this case the extended upper
-;; bits do not matter.
-(define_insn "*tst<mode>_t_zero"
- [(set (reg:SI T_REG)
- (eq:SI
- (subreg:QIHI
- (and:SI (match_operand:SI 0 "arith_reg_operand" "%r")
- (match_operand:SI 1 "arith_reg_operand" "r")) <lowpart_le>)
- (const_int 0)))]
- "TARGET_SH1 && TARGET_LITTLE_ENDIAN"
- "tst %0,%1"
- [(set_attr "type" "mt_group")])
-
-(define_insn "*tst<mode>_t_zero"
- [(set (reg:SI T_REG)
- (eq:SI
- (subreg:QIHI
- (and:SI (match_operand:SI 0 "arith_reg_operand" "%r")
- (match_operand:SI 1 "arith_reg_operand" "r")) <lowpart_be>)
- (const_int 0)))]
- "TARGET_SH1 && TARGET_BIG_ENDIAN"
- "tst %0,%1"
- [(set_attr "type" "mt_group")])
-
;; Extract LSB, negate and store in T bit.
(define_insn "tstsi_t_and_not"
[(set (reg:SI T_REG)
Index: gcc/testsuite/gcc.target/sh/pr53988.c
===================================================================
--- gcc/testsuite/gcc.target/sh/pr53988.c (revision 221258)
+++ gcc/testsuite/gcc.target/sh/pr53988.c (working copy)
@@ -5,9 +5,9 @@
/* { dg-do compile } */
/* { dg-options "-O1" } */
/* { dg-skip-if "" { "sh*-*-*" } { "-m5*"} { "" } } */
-/* { dg-final { scan-assembler-times "tst\tr" 8 } } */
-/* { dg-final { scan-assembler-not "tst\t#255" } } */
-/* { dg-final { scan-assembler-not "exts|extu|and|movu" } } */
+/* { dg-final { scan-assembler-times "tst\tr" 8 { xfail *-*-*} } } */
+/* { dg-final { scan-assembler-not "tst\t#255" { xfail *-*-*} } } */
+/* { dg-final { scan-assembler-not "exts|extu|and|movu" { xfail *-*-*} } } */
int
test00 (char* a, char* b, int c, int d)
