Rather than using unspecs in doloop insns to stop combine creating
these insns, use legitimate_combined_insn.
I'm not sure why the original patch implementing
legitimate_combined_insn did not store the result of recog to the insn
but it seems good to me, and would allow the recog call in
ix86_legitimate_combined_insn to be omitted. (I tested that too, not
shown here.)
Bootstrapped and regression tested powerpc64le-linux, powerpc64-linux,
x86_64-linux. OK for mainline?
PR target/72749
* combine.c (recog_for_combine_1): Set INSN_CODE before calling
target legitimate_combined_insn.
* config/rs6000/rs6000.c (TARGET_LEGITIMATE_COMBINED_INSN): Define.
(rs6000_legitimate_combined_insn): New function.
* config/rs6000/rs6000.md (UNSPEC_DOLOOP): Delete, and remove
all uses.
(ctr<mode>_internal3): Rename from *ctr<mode>_internal5.
(ctr<mode>_internal4): Rename from *ctr<mode>_internal6.
(ctr<mode>_internal1, ctr<mode>_internal2): Remove '*' from name.
diff --git a/gcc/combine.c b/gcc/combine.c
index 3043f2a..73a74ac 100644
--- a/gcc/combine.c
+++ b/gcc/combine.c
@@ -11199,6 +11199,7 @@ recog_for_combine_1 (rtx *pnewpat, rtx_insn *insn, rtx
*pnotes)
old_icode = INSN_CODE (insn);
PATTERN (insn) = pat;
REG_NOTES (insn) = notes;
+ INSN_CODE (insn) = insn_code_number;
/* Allow targets to reject combined insn. */
if (!targetm.legitimate_combined_insn (insn))
diff --git a/gcc/config/rs6000/rs6000.c b/gcc/config/rs6000/rs6000.c
index 02b521c..76ba81b 100644
--- a/gcc/config/rs6000/rs6000.c
+++ b/gcc/config/rs6000/rs6000.c
@@ -1558,6 +1558,9 @@ static const struct attribute_spec
rs6000_attribute_table[] =
#undef TARGET_CONST_NOT_OK_FOR_DEBUG_P
#define TARGET_CONST_NOT_OK_FOR_DEBUG_P rs6000_const_not_ok_for_debug_p
+#undef TARGET_LEGITIMATE_COMBINED_INSN
+#define TARGET_LEGITIMATE_COMBINED_INSN rs6000_legitimate_combined_insn
+
#undef TARGET_ASM_FUNCTION_PROLOGUE
#define TARGET_ASM_FUNCTION_PROLOGUE rs6000_output_function_prologue
#undef TARGET_ASM_FUNCTION_EPILOGUE
@@ -9076,6 +9079,49 @@ rs6000_const_not_ok_for_debug_p (rtx x)
return false;
}
+
+/* Implement the TARGET_LEGITIMATE_COMBINED_INSN hook. */
+
+static bool
+rs6000_legitimate_combined_insn (rtx_insn *insn)
+{
+ switch (INSN_CODE (insn))
+ {
+ /* Reject creating doloop insns. Combine should not be allowed
+ to create these for a number of reasons:
+ 1) In a nested loop, if combine creates one of these in an
+ outer loop and the register allocator happens to allocate ctr
+ to the outer loop insn, then the inner loop can't use ctr.
+ Inner loops ought to be more highly optimized.
+ 2) Combine often wants to create one of these from what was
+ originally a three insn sequence, first combining the three
+ insns to two, then to ctrsi/ctrdi. When ctrsi/ctrdi is not
+ allocated ctr, the splitter takes use back to the three insn
+ sequence. It's better to stop combine at the two insn
+ sequence.
+ 3) Faced with not being able to allocate ctr for ctrsi/crtdi
+ insns, the register allocator sometimes uses floating point
+ or vector registers for the pseudo. Since ctrsi/ctrdi is a
+ jump insn and output reloads are not implemented for jumps,
+ the ctrsi/ctrdi splitters need to handle all possible cases.
+ That's a pain, and it gets to be seriously difficult when a
+ splitter that runs after reload needs memory to transfer from
+ a gpr to fpr. See PR70098 and PR71763 which are not fixed
+ for the difficult case. It's better to not create problems
+ in the first place. */
+ case CODE_FOR_ctrsi_internal1:
+ case CODE_FOR_ctrdi_internal1:
+ case CODE_FOR_ctrsi_internal2:
+ case CODE_FOR_ctrdi_internal2:
+ case CODE_FOR_ctrsi_internal3:
+ case CODE_FOR_ctrdi_internal3:
+ case CODE_FOR_ctrsi_internal4:
+ case CODE_FOR_ctrdi_internal4:
+ return false;
+ }
+ return true;
+}
+
/* Construct the SYMBOL_REF for the tls_get_addr function. */
static GTY(()) rtx rs6000_tls_symbol;
diff --git a/gcc/config/rs6000/rs6000.md b/gcc/config/rs6000/rs6000.md
index f7c1ab2..9442b07 100644
--- a/gcc/config/rs6000/rs6000.md
+++ b/gcc/config/rs6000/rs6000.md
@@ -149,7 +149,6 @@ (define_c_enum "unspec"
UNSPEC_IEEE128_MOVE
UNSPEC_IEEE128_CONVERT
UNSPEC_SIGNBIT
- UNSPEC_DOLOOP
UNSPEC_SF_FROM_SI
UNSPEC_SI_FROM_SF
])
@@ -12740,7 +12739,6 @@ (define_expand "ctr<mode>"
(set (match_dup 0)
(plus:P (match_dup 0)
(const_int -1)))
- (unspec [(const_int 0)] UNSPEC_DOLOOP)
(clobber (match_scratch:CC 2 ""))
(clobber (match_scratch:P 3 ""))])]
""
@@ -12751,9 +12749,8 @@ (define_expand "ctr<mode>"
;; JUMP_INSNs.
;; For the length attribute to be calculated correctly, the
;; label MUST be operand 0.
-;; The UNSPEC is present to prevent combine creating this pattern.
-(define_insn "*ctr<mode>_internal1"
+(define_insn "ctr<mode>_internal1"
[(set (pc)
(if_then_else (ne (match_operand:P 1 "register_operand" "c,*b,*b,*b")
(const_int 1))
@@ -12762,7 +12759,6 @@ (define_insn "*ctr<mode>_internal1"
(set (match_operand:P 2 "nonimmediate_operand" "=1,*r,m,*d*wi*c*l")
(plus:P (match_dup 1)
(const_int -1)))
- (unspec [(const_int 0)] UNSPEC_DOLOOP)
(clobber (match_scratch:CC 3 "=X,&x,&x,&x"))
(clobber (match_scratch:P 4 "=X,X,&r,r"))]
""
@@ -12778,7 +12774,7 @@ (define_insn "*ctr<mode>_internal1"
[(set_attr "type" "branch")
(set_attr "length" "*,16,20,20")])
-(define_insn "*ctr<mode>_internal2"
+(define_insn "ctr<mode>_internal2"
[(set (pc)
(if_then_else (ne (match_operand:P 1 "register_operand" "c,*b,*b,*b")
(const_int 1))
@@ -12787,7 +12783,6 @@ (define_insn "*ctr<mode>_internal2"
(set (match_operand:P 2 "nonimmediate_operand" "=1,*r,m,*d*wi*c*l")
(plus:P (match_dup 1)
(const_int -1)))
- (unspec [(const_int 0)] UNSPEC_DOLOOP)
(clobber (match_scratch:CC 3 "=X,&x,&x,&x"))
(clobber (match_scratch:P 4 "=X,X,&r,r"))]
""
@@ -12805,7 +12800,7 @@ (define_insn "*ctr<mode>_internal2"
;; Similar but use EQ
-(define_insn "*ctr<mode>_internal5"
+(define_insn "ctr<mode>_internal3"
[(set (pc)
(if_then_else (eq (match_operand:P 1 "register_operand" "c,*b,*b,*b")
(const_int 1))
@@ -12814,7 +12809,6 @@ (define_insn "*ctr<mode>_internal5"
(set (match_operand:P 2 "nonimmediate_operand" "=1,*r,m,*d*wi*c*l")
(plus:P (match_dup 1)
(const_int -1)))
- (unspec [(const_int 0)] UNSPEC_DOLOOP)
(clobber (match_scratch:CC 3 "=X,&x,&x,&x"))
(clobber (match_scratch:P 4 "=X,X,&r,r"))]
""
@@ -12830,7 +12824,7 @@ (define_insn "*ctr<mode>_internal5"
[(set_attr "type" "branch")
(set_attr "length" "*,16,20,20")])
-(define_insn "*ctr<mode>_internal6"
+(define_insn "ctr<mode>_internal4"
[(set (pc)
(if_then_else (eq (match_operand:P 1 "register_operand" "c,*b,*b,*b")
(const_int 1))
@@ -12839,7 +12833,6 @@ (define_insn "*ctr<mode>_internal6"
(set (match_operand:P 2 "nonimmediate_operand" "=1,*r,m,*d*wi*c*l")
(plus:P (match_dup 1)
(const_int -1)))
- (unspec [(const_int 0)] UNSPEC_DOLOOP)
(clobber (match_scratch:CC 3 "=X,&x,&x,&x"))
(clobber (match_scratch:P 4 "=X,X,&r,r"))]
""
@@ -12866,7 +12859,6 @@ (define_split
(match_operand 6 "" "")))
(set (match_operand:P 0 "int_reg_operand" "")
(plus:P (match_dup 1) (const_int -1)))
- (unspec [(const_int 0)] UNSPEC_DOLOOP)
(clobber (match_scratch:CC 3 ""))
(clobber (match_scratch:P 4 ""))]
"reload_completed"
@@ -12892,7 +12884,6 @@ (define_split
(match_operand 6 "" "")))
(set (match_operand:P 0 "nonimmediate_operand" "")
(plus:P (match_dup 1) (const_int -1)))
- (unspec [(const_int 0)] UNSPEC_DOLOOP)
(clobber (match_scratch:CC 3 ""))
(clobber (match_scratch:P 4 ""))]
"reload_completed && ! gpc_reg_operand (operands[0], SImode)"
diff --git a/gcc/testsuite/gcc.c-torture/compile/pr72749.c
b/gcc/testsuite/gcc.c-torture/compile/pr72749.c
new file mode 100644
index 0000000..2ef4d9a
--- /dev/null
+++ b/gcc/testsuite/gcc.c-torture/compile/pr72749.c
@@ -0,0 +1,21 @@
+/* { dg-options "-O2 -fsched2-use-superblocks" } */
+
+int as;
+
+void
+ji (int *x4)
+{
+ if (0)
+ {
+ unsigned int pv;
+
+ while (as < 0)
+ {
+ for (*x4 = 0; *x4 < 1; ++(*x4))
+yj:
+ x4 = (int *)&pv;
+ ++as;
+ }
+ }
+ goto yj;
+}
--
Alan Modra
Australia Development Lab, IBM
