* [PATCH] i386: Improve workaround for PR82524 LRA limitation [PR85730]
@ 2021-10-12 16:24 Uros Bizjak
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From: Uros Bizjak @ 2021-10-12 16:24 UTC (permalink / raw)
To: gcc-patches
[-- Attachment #1: Type: text/plain, Size: 1544 bytes --]
As explained in PR82524, LRA is not able to reload strict_low_part inout
operand with matched input operand. The patch introduces a workaround,
where we allow LRA to generate an instruction with non-matched input operand
which is split post reload to an instruction that inserts non-matched input
operand to an inout operand and the instruction that uses matched operand.
The generated code improves from:
movsbl %dil, %edx
movl %edi, %eax
sall $3, %edx
movb %dl, %al
to:
movl %edi, %eax
movb %dil, %al
salb $3, %al
which is still not optimal, but the code is one instruction shorter and
does not use a temporary register.
2021-10-12 Uroš Bizjak <ubizjak@gmail.com>
gcc/
PR target/85730
PR target/82524
* config/i386/i386.md (*add<mode>_1_slp): Rewrite as
define_insn_and_split pattern. Add alternative 1 and split it
post reload to insert operand 1 into the low part of operand 0.
(*sub<mode>_1_slp): Ditto.
(*and<mode>_1_slp): Ditto.
(*<any_or:code><mode>_1_slp): Ditto.
(*ashl<mode>3_1_slp): Ditto.
(*<any_shiftrt:insn><mode>3_1_slp): Ditto.
(*<any_rotate:insn><mode>3_1_slp): Ditto.
(*neg<mode>_1_slp): New insn_and_split pattern.
(*one_cmpl<mode>_1_slp): Ditto.
gcc/testsuite/
PR target/85730
PR target/82524
* gcc.target/i386/pr85730.c: New test.
Bootstrapped and regression tested on x86_64-linux-gnu {,-m32}.
Pushed to master.
Uros.
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diff --git a/gcc/config/i386/i386.md b/gcc/config/i386/i386.md
index c7ae4ac5fbc..e733a40fc90 100644
--- a/gcc/config/i386/i386.md
+++ b/gcc/config/i386/i386.md
@@ -5730,16 +5730,17 @@
(symbol_ref "!TARGET_PARTIAL_REG_STALL")]
(symbol_ref "true")))])
-(define_insn "*add<mode>_1_slp"
- [(set (strict_low_part (match_operand:SWI12 0 "register_operand" "+<r>"))
- (plus:SWI12 (match_operand:SWI12 1 "nonimmediate_operand" "%0")
- (match_operand:SWI12 2 "general_operand" "<r>mn")))
+;; Alternative 1 is needed to work around LRA limitation, see PR82524.
+(define_insn_and_split "*add<mode>_1_slp"
+ [(set (strict_low_part (match_operand:SWI12 0 "register_operand" "+<r>,<r>"))
+ (plus:SWI12 (match_operand:SWI12 1 "nonimmediate_operand" "%0,!<r>")
+ (match_operand:SWI12 2 "general_operand" "<r>mn,<r>mn")))
(clobber (reg:CC FLAGS_REG))]
- "(!TARGET_PARTIAL_REG_STALL || optimize_function_for_size_p (cfun))
- /* FIXME: without this LRA can't reload this pattern, see PR82524. */
- && (rtx_equal_p (operands[0], operands[1])
- || rtx_equal_p (operands[0], operands[2]))"
+ "!TARGET_PARTIAL_REG_STALL || optimize_function_for_size_p (cfun)"
{
+ if (which_alternative)
+ return "#";
+
switch (get_attr_type (insn))
{
case TYPE_INCDEC:
@@ -5758,6 +5759,13 @@
return "add{<imodesuffix>}\t{%2, %0|%0, %2}";
}
}
+ "&& reload_completed"
+ [(set (strict_low_part (match_dup 0)) (match_dup 1))
+ (parallel
+ [(set (strict_low_part (match_dup 0))
+ (plus:SWI12 (match_dup 0) (match_dup 2)))
+ (clobber (reg:CC FLAGS_REG))])]
+ ""
[(set (attr "type")
(if_then_else (match_operand:QI 2 "incdec_operand")
(const_string "incdec")
@@ -6676,15 +6684,23 @@
[(set_attr "type" "alu")
(set_attr "mode" "SI")])
-(define_insn "*sub<mode>_1_slp"
- [(set (strict_low_part (match_operand:SWI12 0 "register_operand" "+<r>"))
- (minus:SWI12 (match_operand:SWI12 1 "register_operand" "0")
- (match_operand:SWI12 2 "general_operand" "<r>mn")))
+;; Alternative 1 is needed to work around LRA limitation, see PR82524.
+(define_insn_and_split "*sub<mode>_1_slp"
+ [(set (strict_low_part (match_operand:SWI12 0 "register_operand" "+<r>,<r>"))
+ (minus:SWI12 (match_operand:SWI12 1 "register_operand" "0,!<r>")
+ (match_operand:SWI12 2 "general_operand" "<r>mn,<r>mn")))
(clobber (reg:CC FLAGS_REG))]
- "(!TARGET_PARTIAL_REG_STALL || optimize_function_for_size_p (cfun))
- /* FIXME: without this LRA can't reload this pattern, see PR82524. */
- && rtx_equal_p (operands[0], operands[1])"
- "sub{<imodesuffix>}\t{%2, %0|%0, %2}"
+ "!TARGET_PARTIAL_REG_STALL || optimize_function_for_size_p (cfun)"
+ "@
+ sub{<imodesuffix>}\t{%2, %0|%0, %2}
+ #"
+ "&& reload_completed"
+ [(set (strict_low_part (match_dup 0)) (match_dup 1))
+ (parallel
+ [(set (strict_low_part (match_dup 0))
+ (minus:SWI12 (match_dup 0) (match_dup 2)))
+ (clobber (reg:CC FLAGS_REG))])]
+ ""
[(set_attr "type" "alu")
(set_attr "mode" "<MODE>")])
@@ -9606,16 +9622,23 @@
(symbol_ref "!TARGET_PARTIAL_REG_STALL")]
(symbol_ref "true")))])
-(define_insn "*and<mode>_1_slp"
- [(set (strict_low_part (match_operand:SWI12 0 "register_operand" "+<r>"))
- (and:SWI12 (match_operand:SWI12 1 "nonimmediate_operand" "%0")
- (match_operand:SWI12 2 "general_operand" "<r>mn")))
+;; Alternative 1 is needed to work around LRA limitation, see PR82524.
+(define_insn_and_split "*and<mode>_1_slp"
+ [(set (strict_low_part (match_operand:SWI12 0 "register_operand" "+<r>,<r>"))
+ (and:SWI12 (match_operand:SWI12 1 "nonimmediate_operand" "%0,!<r>")
+ (match_operand:SWI12 2 "general_operand" "<r>mn,<r>mn")))
(clobber (reg:CC FLAGS_REG))]
- "(!TARGET_PARTIAL_REG_STALL || optimize_function_for_size_p (cfun))
- /* FIXME: without this LRA can't reload this pattern, see PR82524. */
- && (rtx_equal_p (operands[0], operands[1])
- || rtx_equal_p (operands[0], operands[2]))"
- "and{<imodesuffix>}\t{%2, %0|%0, %2}"
+ "!TARGET_PARTIAL_REG_STALL || optimize_function_for_size_p (cfun)"
+ "@
+ and{<imodesuffix>}\t{%2, %0|%0, %2}
+ #"
+ "&& reload_completed"
+ [(set (strict_low_part (match_dup 0)) (match_dup 1))
+ (parallel
+ [(set (strict_low_part (match_dup 0))
+ (and:SWI12 (match_dup 0) (match_dup 2)))
+ (clobber (reg:CC FLAGS_REG))])]
+ ""
[(set_attr "type" "alu")
(set_attr "mode" "<MODE>")])
@@ -10199,16 +10222,23 @@
(symbol_ref "!TARGET_PARTIAL_REG_STALL")]
(symbol_ref "true")))])
-(define_insn "*<code><mode>_1_slp"
- [(set (strict_low_part (match_operand:SWI12 0 "register_operand" "+<r>"))
- (any_or:SWI12 (match_operand:SWI12 1 "nonimmediate_operand" "%0")
- (match_operand:SWI12 2 "general_operand" "<r>mn")))
+;; Alternative 1 is needed to work around LRA limitation, see PR82524.
+(define_insn_and_split "*<code><mode>_1_slp"
+ [(set (strict_low_part (match_operand:SWI12 0 "register_operand" "+<r>,<r>"))
+ (any_or:SWI12 (match_operand:SWI12 1 "nonimmediate_operand" "%0,!<r>")
+ (match_operand:SWI12 2 "general_operand" "<r>mn,<r>mn")))
(clobber (reg:CC FLAGS_REG))]
- "(!TARGET_PARTIAL_REG_STALL || optimize_function_for_size_p (cfun))
- /* FIXME: without this LRA can't reload this pattern, see PR82524. */
- && (rtx_equal_p (operands[0], operands[1])
- || rtx_equal_p (operands[0], operands[2]))"
- "<logic>{<imodesuffix>}\t{%2, %0|%0, %2}"
+ "!TARGET_PARTIAL_REG_STALL || optimize_function_for_size_p (cfun)"
+ "@
+ <logic>{<imodesuffix>}\t{%2, %0|%0, %2}
+ #"
+ "&& reload_completed"
+ [(set (strict_low_part (match_dup 0)) (match_dup 1))
+ (parallel
+ [(set (strict_low_part (match_dup 0))
+ (any_or:SWI12 (match_dup 0) (match_dup 2)))
+ (clobber (reg:CC FLAGS_REG))])]
+ ""
[(set_attr "type" "alu")
(set_attr "mode" "<MODE>")])
@@ -10505,6 +10535,25 @@
[(set_attr "type" "negnot")
(set_attr "mode" "SI")])
+;; Alternative 1 is needed to work around LRA limitation, see PR82524.
+(define_insn_and_split "*neg<mode>_1_slp"
+ [(set (strict_low_part (match_operand:SWI12 0 "register_operand" "+<r>,<r>"))
+ (neg:SWI12 (match_operand:SWI12 1 "register_operand" "0,!<r>")))
+ (clobber (reg:CC FLAGS_REG))]
+ "!TARGET_PARTIAL_REG_STALL || optimize_function_for_size_p (cfun)"
+ "@
+ neg{<imodesuffix>}\t%0
+ #"
+ "&& reload_completed"
+ [(set (strict_low_part (match_dup 0)) (match_dup 1))
+ (parallel
+ [(set (strict_low_part (match_dup 0))
+ (neg:SWI12 (match_dup 0)))
+ (clobber (reg:CC FLAGS_REG))])]
+ ""
+ [(set_attr "type" "negnot")
+ (set_attr "mode" "<MODE>")])
+
(define_insn "*neg<mode>_2"
[(set (reg FLAGS_REG)
(compare
@@ -11060,6 +11109,22 @@
(symbol_ref "!TARGET_PARTIAL_REG_STALL")]
(symbol_ref "true")))])
+;; Alternative 1 is needed to work around LRA limitation, see PR82524.
+(define_insn_and_split "*one_cmpl<mode>_1_slp"
+ [(set (strict_low_part (match_operand:SWI12 0 "register_operand" "+<r>,<r>"))
+ (not:SWI12 (match_operand:SWI12 1 "register_operand" "0,!<r>")))]
+ "!TARGET_PARTIAL_REG_STALL || optimize_function_for_size_p (cfun)"
+ "@
+ not{<imodesuffix>}\t%0
+ #"
+ "&& reload_completed"
+ [(set (strict_low_part (match_dup 0)) (match_dup 1))
+ (set (strict_low_part (match_dup 0))
+ (not:SWI12 (match_dup 0)))]
+ ""
+ [(set_attr "type" "negnot")
+ (set_attr "mode" "<MODE>")])
+
(define_insn "*one_cmpl<mode>2_2"
[(set (reg FLAGS_REG)
(compare (not:SWI (match_operand:SWI 1 "nonimmediate_operand" "0"))
@@ -11638,15 +11703,17 @@
(symbol_ref "!TARGET_PARTIAL_REG_STALL")]
(symbol_ref "true")))])
-(define_insn "*ashl<mode>3_1_slp"
- [(set (strict_low_part (match_operand:SWI12 0 "register_operand" "+<r>"))
- (ashift:SWI12 (match_operand:SWI12 1 "register_operand" "0")
- (match_operand:QI 2 "nonmemory_operand" "cI")))
+;; Alternative 1 is needed to work around LRA limitation, see PR82524.
+(define_insn_and_split "*ashl<mode>3_1_slp"
+ [(set (strict_low_part (match_operand:SWI12 0 "register_operand" "+<r>,<r>"))
+ (ashift:SWI12 (match_operand:SWI12 1 "register_operand" "0,!<r>")
+ (match_operand:QI 2 "nonmemory_operand" "cI,cI")))
(clobber (reg:CC FLAGS_REG))]
- "(!TARGET_PARTIAL_REG_STALL || optimize_function_for_size_p (cfun))
- /* FIXME: without this LRA can't reload this pattern, see PR82524. */
- && rtx_equal_p (operands[0], operands[1])"
+ "!TARGET_PARTIAL_REG_STALL || optimize_function_for_size_p (cfun)"
{
+ if (which_alternative)
+ return "#";
+
switch (get_attr_type (insn))
{
case TYPE_ALU:
@@ -11661,6 +11728,13 @@
return "sal{<imodesuffix>}\t{%2, %0|%0, %2}";
}
}
+ "&& reload_completed"
+ [(set (strict_low_part (match_dup 0)) (match_dup 1))
+ (parallel
+ [(set (strict_low_part (match_dup 0))
+ (ashift:SWI12 (match_dup 0) (match_dup 2)))
+ (clobber (reg:CC FLAGS_REG))])]
+ ""
[(set (attr "type")
(cond [(and (match_test "TARGET_DOUBLE_WITH_ADD")
(match_operand 2 "const1_operand"))
@@ -12356,21 +12430,30 @@
(const_string "*")))
(set_attr "mode" "HI")])
-(define_insn "*<insn><mode>3_1_slp"
- [(set (strict_low_part (match_operand:SWI12 0 "register_operand" "+<r>"))
- (any_shiftrt:SWI12 (match_operand:SWI12 1 "register_operand" "0")
- (match_operand:QI 2 "nonmemory_operand" "cI")))
+;; Alternative 1 is needed to work around LRA limitation, see PR82524.
+(define_insn_and_split "*<insn><mode>3_1_slp"
+ [(set (strict_low_part (match_operand:SWI12 0 "register_operand" "+<r>,<r>"))
+ (any_shiftrt:SWI12 (match_operand:SWI12 1 "register_operand" "0,!<r>")
+ (match_operand:QI 2 "nonmemory_operand" "cI,cI")))
(clobber (reg:CC FLAGS_REG))]
- "(!TARGET_PARTIAL_REG_STALL || optimize_function_for_size_p (cfun))
- /* FIXME: without this LRA can't reload this pattern, see PR82524. */
- && rtx_equal_p (operands[0], operands[1])"
+ "!TARGET_PARTIAL_REG_STALL || optimize_function_for_size_p (cfun)"
{
+ if (which_alternative)
+ return "#";
+
if (operands[2] == const1_rtx
&& (TARGET_SHIFT1 || optimize_function_for_size_p (cfun)))
return "<shift>{<imodesuffix>}\t%0";
else
return "<shift>{<imodesuffix>}\t{%2, %0|%0, %2}";
}
+ "&& reload_completed"
+ [(set (strict_low_part (match_dup 0)) (match_dup 1))
+ (parallel
+ [(set (strict_low_part (match_dup 0))
+ (any_shiftrt:SWI12 (match_dup 0) (match_dup 2)))
+ (clobber (reg:CC FLAGS_REG))])]
+ ""
[(set_attr "type" "ishift")
(set (attr "length_immediate")
(if_then_else
@@ -12814,21 +12897,30 @@
(const_string "*")))
(set_attr "mode" "<MODE>")])
-(define_insn "*<insn><mode>3_1_slp"
- [(set (strict_low_part (match_operand:SWI12 0 "register_operand" "+<r>"))
- (any_rotate:SWI12 (match_operand:SWI12 1 "register_operand" "0")
- (match_operand:QI 2 "nonmemory_operand" "cI")))
+;; Alternative 1 is needed to work around LRA limitation, see PR82524.
+(define_insn_and_split "*<insn><mode>3_1_slp"
+ [(set (strict_low_part (match_operand:SWI12 0 "register_operand" "+<r>,<r>"))
+ (any_rotate:SWI12 (match_operand:SWI12 1 "register_operand" "0,!<r>")
+ (match_operand:QI 2 "nonmemory_operand" "cI,cI")))
(clobber (reg:CC FLAGS_REG))]
- "(!TARGET_PARTIAL_REG_STALL || optimize_function_for_size_p (cfun))
- /* FIXME: without this LRA can't reload this pattern, see PR82524. */
- && rtx_equal_p (operands[0], operands[1])"
+ "!TARGET_PARTIAL_REG_STALL || optimize_function_for_size_p (cfun)"
{
+ if (which_alternative)
+ return "#";
+
if (operands[2] == const1_rtx
&& (TARGET_SHIFT1 || optimize_function_for_size_p (cfun)))
return "<rotate>{<imodesuffix>}\t%0";
else
return "<rotate>{<imodesuffix>}\t{%2, %0|%0, %2}";
}
+ "&& reload_completed"
+ [(set (strict_low_part (match_dup 0)) (match_dup 1))
+ (parallel
+ [(set (strict_low_part (match_dup 0))
+ (any_rotate:SWI12 (match_dup 0) (match_dup 2)))
+ (clobber (reg:CC FLAGS_REG))])]
+ ""
[(set_attr "type" "rotate")
(set (attr "length_immediate")
(if_then_else
diff --git a/gcc/testsuite/gcc.target/i386/pr85730.c b/gcc/testsuite/gcc.target/i386/pr85730.c
new file mode 100644
index 00000000000..b2790166689
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/pr85730.c
@@ -0,0 +1,95 @@
+/* PR target/85730 */
+/* { dg-do compile } */
+/* { dg-options "-O2 -mno-sse4" } */
+
+typedef char V __attribute__((vector_size(4)));
+
+V
+test_and (V v, char c)
+{
+ v[0] &= c;
+
+ return v;
+}
+
+/* { dg-final { scan-assembler "\[ \t\]andb" } } */
+
+V
+test_or (V v, char c)
+{
+ v[0] |= c;
+
+ return v;
+}
+
+/* { dg-final { scan-assembler "\[ \t\]orb" } } */
+
+V
+test_xor (V v, char c)
+{
+ v[0] ^= c;
+
+ return v;
+}
+
+/* { dg-final { scan-assembler "\[ \t\]xorb" } } */
+
+V
+test_not (V v)
+{
+ v[0] = ~v[0];
+
+ return v;
+}
+
+/* { dg-final { scan-assembler "\[ \t\]notb" } } */
+
+V
+test_sal (V v)
+{
+ v[0] <<= 3;
+
+ return v;
+}
+
+/* { dg-final { scan-assembler "\[ \t\]salb" } } */
+
+V
+test_sar (V v)
+{
+ v[0] >>= 3;
+
+ return v;
+}
+
+/* { dg-final { scan-assembler "\[ \t\]sarb" } } */
+
+V
+test_add (V v, char c)
+{
+ v[0] += c;
+
+ return v;
+}
+
+/* { dg-final { scan-assembler "\[ \t\]addb" } } */
+
+V
+test_sub (V v, char c)
+{
+ v[0] -= c;
+
+ return v;
+}
+
+/* { dg-final { scan-assembler "\[ \t\]subb" } } */
+
+V
+test_neg (V v)
+{
+ v[0] = -v[0];
+
+ return v;
+}
+
+/* { dg-final { scan-assembler "\[ \t\]negb" } } */
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