Hi!
The following testcase ICEs on aarch64 apparently since the introduction of
the aarch64 port. The reason is that the {ashl,ashr,lshr}<mode>3 expanders
completely unnecessarily FAIL; if operands[2] is something other than
a CONST_INT or REG or MEM and the middle-end code can't cope with the
pattern giving up in these cases. All the expanders use general_operand
predicate for the shift amount operand, but then have just a special case
for CONST_INT (if in-bound, emit an immediate shift, otherwise force into
REG), or MEM (force into REG), or REG (that is the case it handles).
In the testcase, operands[2] is a lowpart SUBREG of a REG, which is valid
general_operand.
I don't see any reason what is magic about MEMs that it should be forced
into REG and others like SUBREGs that it shouldn't, there isn't even a
reason to check for !REG_P because force_reg will do nothing if the operand
is already a REG, and otherwise can handle general_operand just fine.
Fixed thusly, bootstrapped/regtested on aarch64-linux, ok for trunk and
after a while for backports?
2020-04-06 Jakub Jelinek <ja...@redhat.com>
PR target/94488
* config/aarch64/aarch64-simd.md (ashl<mode>3, lshr<mode>3,
ashr<mode>3): Force operands[2] into reg whenever it is not CONST_INT.
Assume it is a REG after that instead of testing it and doing FAIL
otherwise. Formatting fix.
* gcc.c-torture/compile/pr94488.c: New test.
--- gcc/config/aarch64/aarch64-simd.md.jj 2020-03-09 12:43:00.742038043
+0100
+++ gcc/config/aarch64/aarch64-simd.md 2020-04-06 08:28:35.527116650 +0200
@@ -1106,30 +1106,18 @@ (define_expand "ashl<mode>3"
DONE;
}
else
- {
- operands[2] = force_reg (SImode, operands[2]);
- }
- }
- else if (MEM_P (operands[2]))
- {
- operands[2] = force_reg (SImode, operands[2]);
- }
-
- if (REG_P (operands[2]))
- {
- rtx tmp = gen_reg_rtx (<MODE>mode);
- emit_insn (gen_aarch64_simd_dup<mode> (tmp,
- convert_to_mode (<VEL>mode,
- operands[2],
- 0)));
- emit_insn (gen_aarch64_simd_reg_sshl<mode> (operands[0], operands[1],
- tmp));
- DONE;
+ operands[2] = force_reg (SImode, operands[2]);
}
else
- FAIL;
-}
-)
+ operands[2] = force_reg (SImode, operands[2]);
+
+ rtx tmp = gen_reg_rtx (<MODE>mode);
+ emit_insn (gen_aarch64_simd_dup<mode> (tmp, convert_to_mode (<VEL>mode,
+ operands[2],
+ 0)));
+ emit_insn (gen_aarch64_simd_reg_sshl<mode> (operands[0], operands[1], tmp));
+ DONE;
+})
(define_expand "lshr<mode>3"
[(match_operand:VDQ_I 0 "register_operand")
@@ -1155,28 +1143,18 @@ (define_expand "lshr<mode>3"
else
operands[2] = force_reg (SImode, operands[2]);
}
- else if (MEM_P (operands[2]))
- {
- operands[2] = force_reg (SImode, operands[2]);
- }
-
- if (REG_P (operands[2]))
- {
- rtx tmp = gen_reg_rtx (SImode);
- rtx tmp1 = gen_reg_rtx (<MODE>mode);
- emit_insn (gen_negsi2 (tmp, operands[2]));
- emit_insn (gen_aarch64_simd_dup<mode> (tmp1,
- convert_to_mode (<VEL>mode,
- tmp, 0)));
- emit_insn (gen_aarch64_simd_reg_shl<mode>_unsigned (operands[0],
- operands[1],
- tmp1));
- DONE;
- }
else
- FAIL;
-}
-)
+ operands[2] = force_reg (SImode, operands[2]);
+
+ rtx tmp = gen_reg_rtx (SImode);
+ rtx tmp1 = gen_reg_rtx (<MODE>mode);
+ emit_insn (gen_negsi2 (tmp, operands[2]));
+ emit_insn (gen_aarch64_simd_dup<mode> (tmp1,
+ convert_to_mode (<VEL>mode, tmp, 0)));
+ emit_insn (gen_aarch64_simd_reg_shl<mode>_unsigned (operands[0], operands[1],
+ tmp1));
+ DONE;
+})
(define_expand "ashr<mode>3"
[(match_operand:VDQ_I 0 "register_operand")
@@ -1202,28 +1180,18 @@ (define_expand "ashr<mode>3"
else
operands[2] = force_reg (SImode, operands[2]);
}
- else if (MEM_P (operands[2]))
- {
- operands[2] = force_reg (SImode, operands[2]);
- }
-
- if (REG_P (operands[2]))
- {
- rtx tmp = gen_reg_rtx (SImode);
- rtx tmp1 = gen_reg_rtx (<MODE>mode);
- emit_insn (gen_negsi2 (tmp, operands[2]));
- emit_insn (gen_aarch64_simd_dup<mode> (tmp1,
- convert_to_mode (<VEL>mode,
- tmp, 0)));
- emit_insn (gen_aarch64_simd_reg_shl<mode>_signed (operands[0],
- operands[1],
- tmp1));
- DONE;
- }
else
- FAIL;
-}
-)
+ operands[2] = force_reg (SImode, operands[2]);
+
+ rtx tmp = gen_reg_rtx (SImode);
+ rtx tmp1 = gen_reg_rtx (<MODE>mode);
+ emit_insn (gen_negsi2 (tmp, operands[2]));
+ emit_insn (gen_aarch64_simd_dup<mode> (tmp1, convert_to_mode (<VEL>mode,
+ tmp, 0)));
+ emit_insn (gen_aarch64_simd_reg_shl<mode>_signed (operands[0], operands[1],
+ tmp1));
+ DONE;
+})
(define_expand "vashl<mode>3"
[(match_operand:VDQ_I 0 "register_operand")
--- gcc/testsuite/gcc.c-torture/compile/pr94488.c.jj 2020-04-06
08:32:43.213374474 +0200
+++ gcc/testsuite/gcc.c-torture/compile/pr94488.c 2020-04-06
08:32:31.879545716 +0200
@@ -0,0 +1,22 @@
+/* PR target/94488 */
+
+typedef unsigned long V __attribute__((__vector_size__(16)));
+typedef long W __attribute__((__vector_size__(16)));
+
+void
+foo (V *x, unsigned long y)
+{
+ *x = *x >> (unsigned int) y;
+}
+
+void
+bar (V *x, unsigned long y)
+{
+ *x = *x << (unsigned int) y;
+}
+
+void
+baz (W *x, unsigned long y)
+{
+ *x = *x >> (unsigned int) y;
+}
Jakub
