x86: Enable *mov<mode>_(and|or) only for -Oz

commit ef26c151c14a87177d46fd3d725e7f82e040e89f
Author: Roger Sayle <roger@nextmovesoftware.com>
Date:   Thu Dec 23 12:33:07 2021 +0000

    x86: PR target/103773: Fix wrong-code with -Oz from pop to memory.

added "*mov<mode>_and" and extended "*mov<mode>_or" to transform
"mov $0,mem" to the shorter "and $0,mem" and "mov $-1,mem" to the shorter
"or $-1,mem" for -Oz.  But the new pattern:

(define_insn "*mov<mode>_and"
  [(set (match_operand:SWI248 0 "memory_operand" "=m")
    (match_operand:SWI248 1 "const0_operand"))
   (clobber (reg:CC FLAGS_REG))]
  "reload_completed"
  "and{<imodesuffix>}\t{%1, %0|%0, %1}"
  [(set_attr "type" "alu1")
   (set_attr "mode" "<MODE>")
   (set_attr "length_immediate" "1")])

and the extended pattern:

(define_insn "*mov<mode>_or"
  [(set (match_operand:SWI248 0 "nonimmediate_operand" "=rm")
    (match_operand:SWI248 1 "constm1_operand"))
   (clobber (reg:CC FLAGS_REG))]
  "reload_completed"
  "or{<imodesuffix>}\t{%1, %0|%0, %1}"
  [(set_attr "type" "alu1")
   (set_attr "mode" "<MODE>")
   (set_attr "length_immediate" "1")])

aren't guarded for -Oz.  As a result, "and $0,mem" and "or $-1,mem" are
generated without -Oz.

1. Change *mov<mode>_and" to define_insn_and_split and split it to
"mov $0,mem" if not -Oz.
2. Change "*mov<mode>_or" to define_insn_and_split and split it to
"mov $-1,mem" if not -Oz.
3. Don't transform "mov $-1,reg" to "push $-1; pop reg" for -Oz since it
should be transformed to "or $-1,reg".

gcc/

	PR target/120427
	* config/i386/i386.md (*mov<mode>_and): Changed to
	define_insn_and_split.  Split it to "mov $0,mem" if not -Oz.
	(*mov<mode>_or): Changed to define_insn_and_split.  Split it
	to "mov $-1,mem" if not -Oz.
	(peephole2): Don't transform "mov $-1,reg" to "push $-1; pop reg"
	for -Oz since it will be transformed to "or $-1,reg".

gcc/testsuite/

	PR target/120427
	* gcc.target/i386/cold-attribute-4.c: Compile with -Oz.
	* gcc.target/i386/pr120427-1.c: New test.
	* gcc.target/i386/pr120427-2.c: Likewise.
	* gcc.target/i386/pr120427-3.c: Likewise.
	* gcc.target/i386/pr120427-4.c: Likewise.

Signed-off-by: H.J. Lu <hjl.tools@gmail.com>

diff --git a/gcc/config/i386/i386.md b/gcc/config/i386/i386.md
index 6bd557431f5ce9146426fa9be4aec5a2b4b5dff5..423ef48e518f18a33878e52231b6779163f027a3 100644 (file)
--- a/gcc/config/i386/i386.md
+++ b/gcc/config/i386/i386.md
@@ -2438,22 +2438,32 @@
    (set_attr "mode" "SI")
    (set_attr "length_immediate" "0")])
 
-(define_insn "*mov<mode>_and"
+;; Generate shorter "and $0,mem" for -Oz.  Split it to "mov $0,mem"
+;; otherwise.
+(define_insn_and_split "*mov<mode>_and"
   [(set (match_operand:SWI248 0 "memory_operand" "=m")
        (match_operand:SWI248 1 "const0_operand"))
    (clobber (reg:CC FLAGS_REG))]
   "reload_completed"
   "and{<imodesuffix>}\t{%1, %0|%0, %1}"
+  "&& !(optimize_insn_for_size_p () && optimize_size > 1)"
+  [(set (match_dup 0) (match_dup 1))]
+  ""
   [(set_attr "type" "alu1")
    (set_attr "mode" "<MODE>")
    (set_attr "length_immediate" "1")])
 
-(define_insn "*mov<mode>_or"
+;; Generate shorter "or $-1,mem" for -Oz.  Split it to "mov $-1,mem"
+;; otherwise.
+(define_insn_and_split "*mov<mode>_or"
   [(set (match_operand:SWI248 0 "nonimmediate_operand" "=rm")
        (match_operand:SWI248 1 "constm1_operand"))
    (clobber (reg:CC FLAGS_REG))]
   "reload_completed"
   "or{<imodesuffix>}\t{%1, %0|%0, %1}"
+  "&& !(optimize_insn_for_size_p () && optimize_size > 1)"
+  [(set (match_dup 0) (match_dup 1))]
+  ""
   [(set_attr "type" "alu1")
    (set_attr "mode" "<MODE>")
    (set_attr "length_immediate" "1")])
@@ -2958,6 +2968,7 @@
        (match_operand:SWI248 1 "const_int_operand"))]
   "optimize_insn_for_size_p () && optimize_size > 1
    && operands[1] != const0_rtx
+   && operands[1] != constm1_rtx
    && IN_RANGE (INTVAL (operands[1]), -128, 127)
    && !ix86_red_zone_used
    && REGNO (operands[0]) != SP_REG"

diff --git a/gcc/testsuite/gcc.target/i386/cold-attribute-4.c b/gcc/testsuite/gcc.target/i386/cold-attribute-4.c
index 37a41e954daf3b189de585cb6a8f1172ac01d126..e0808c539051f67c3b4c62b8f781b81a546ab040 100644 (file)
--- a/gcc/testsuite/gcc.target/i386/cold-attribute-4.c
+++ b/gcc/testsuite/gcc.target/i386/cold-attribute-4.c
@@ -1,5 +1,5 @@
 /* { dg-do compile } */
-/* { dg-options "-O2" } */
+/* { dg-options "-Oz" } */
 #include <string.h>
 
 int

diff --git a/gcc/testsuite/gcc.target/i386/pr120427-1.c b/gcc/testsuite/gcc.target/i386/pr120427-1.c
new file mode 100644 (file)
index 0000000..7f1690e
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/pr120427-1.c
@@ -0,0 +1,28 @@
+/* { dg-do compile } */
+/* { dg-options "-O2 -mtune=sapphirerapids" } */
+/* { dg-final { scan-assembler-not "and\[lq\]?\[\\t \]+\\\$0, \[0-9\]*\\(" } } */
+
+struct __pthread_mutex_s
+{
+  int __lock;
+  unsigned int __count;
+  int __owner;
+  unsigned int __nusers;
+  int __kind;
+  short __spins;
+  short __elision;
+  void *p[2];
+};
+typedef union
+{
+  struct __pthread_mutex_s __data;
+  char __size[40];
+  long int __align;
+} pthread_mutex_t;
+typedef struct { pthread_mutex_t mutex; } __rtld_lock_recursive_t;
+void
+foo (__rtld_lock_recursive_t *lock, int i)
+{
+  lock[i] = (__rtld_lock_recursive_t) {{ { 0, 0, 0, 0, 1,
+      0, 0, { ((void *)0) , ((void *)0) } } }};
+}

diff --git a/gcc/testsuite/gcc.target/i386/pr120427-2.c b/gcc/testsuite/gcc.target/i386/pr120427-2.c
new file mode 100644 (file)
index 0000000..a380c12
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/pr120427-2.c
@@ -0,0 +1,28 @@
+/* { dg-do compile } */
+/* { dg-options "-O2 -mtune=sapphirerapids" } */
+/* { dg-final { scan-assembler-not "or\[lq\]?\[\\t \]+\\\$-1, \[0-9\]*\\(" } } */
+
+struct __pthread_mutex_s
+{
+  int __lock;
+  unsigned int __count;
+  int __owner;
+  unsigned int __nusers;
+  int __kind;
+  short __spins;
+  short __elision;
+  void *p[2];
+};
+typedef union
+{
+  struct __pthread_mutex_s __data;
+  char __size[40];
+  long int __align;
+} pthread_mutex_t;
+typedef struct { pthread_mutex_t mutex; } __rtld_lock_recursive_t;
+void
+foo (__rtld_lock_recursive_t *lock, int i)
+{
+  lock[i] = (__rtld_lock_recursive_t) {{ { -1, -1, -1, -1, 1,
+      -1, -1, { ((void *)-1) , ((void *)-1) } } }};
+}

diff --git a/gcc/testsuite/gcc.target/i386/pr120427-3.c b/gcc/testsuite/gcc.target/i386/pr120427-3.c
new file mode 100644 (file)
index 0000000..951cb1f
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/pr120427-3.c
@@ -0,0 +1,45 @@
+/* { dg-do compile } */
+/* { dg-options "-O2" } */
+
+typedef int SItype __attribute__ ((mode (SI)));
+typedef unsigned int USItype __attribute__ ((mode (SI)));
+typedef unsigned int UDItype __attribute__ ((mode (DI)));
+typedef UDItype __attribute__ ((__may_alias__)) bar_t;
+
+static inline __attribute__((__always_inline__)) SItype
+bar (const bar_t **p, SItype prec)
+{
+  bar_t mslimb = 0;
+  SItype i = 20;
+  SItype n = ((USItype) prec) % 4;
+  if (n)
+    {
+      prec -= n;
+      if (prec == 0)
+       return 1;
+      mslimb = (*p)[i];
+    }
+  while (mslimb == 0)
+    {
+      prec -= 4;
+      if (prec == 0)
+       return 1;
+      --i;
+      mslimb = (*p)[i];
+    }
+  return prec;
+}
+UDItype
+foo (const bar_t *i, SItype iprec)
+{
+  iprec = bar (&i, iprec);
+  USItype aiprec = iprec < 0 ? -iprec : iprec;
+  bar_t msb = *i;
+  UDItype mantissa = 0;
+  if (aiprec % 4)
+    msb &= ((bar_t) 1 << aiprec) - 1;
+  if (aiprec >= 54)
+    mantissa = (UDItype) msb << 32;
+
+  return (mantissa ^ (UDItype) 0x20000000000000);
+}

diff --git a/gcc/testsuite/gcc.target/i386/pr120427-4.c b/gcc/testsuite/gcc.target/i386/pr120427-4.c
new file mode 100644 (file)
index 0000000..2b453b7
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/pr120427-4.c
@@ -0,0 +1,6 @@
+/* { dg-do compile } */
+/* { dg-options "-O2" } */
+
+#include "cold-attribute-4.c"
+
+/* { dg-final { scan-assembler "movl" } } */