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* [PATCH] Fix up r217118 - simplify_binary_operation_1 (PR rtl-optimization/63843)
@ 2014-11-18 22:08 Jakub Jelinek
  2014-11-19  8:49 ` Richard Biener
  0 siblings, 1 reply; 2+ messages in thread
From: Jakub Jelinek @ 2014-11-18 22:08 UTC (permalink / raw)
  To: Richard Biener, Eric Botcazou; +Cc: gcc-patches

Hi!

The case ASHIFTRT: which is meant for this optimization is preceeded by
/* FALLTHRU */ from ROTATE cases, which can't be optimized this way.
Thus, this patch limits this optimization to ASHIFTRT.

Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk?

2014-11-18  Jakub Jelinek  <jakub@redhat.com>

	PR rtl-optimization/63843
	* simplify-rtx.c (simplify_binary_operation_1) <case ASHIFTRT>: For
	optimization of ashiftrt of subreg of lshiftrt, check that code
	is ASHIFTRT.

	* gcc.c-torture/execute/pr63843.c: New test.

--- gcc/simplify-rtx.c.jj	2014-11-18 10:17:01.000000000 +0100
+++ gcc/simplify-rtx.c	2014-11-18 13:44:26.727792683 +0100
@@ -3118,10 +3118,11 @@ simplify_binary_operation_1 (enum rtx_co
          (subreg:M1 (ashiftrt:M2 (reg:M2)
                                  (const_int <c1 + c2>))
           <low_part>).  */
-      if (!VECTOR_MODE_P (mode)
+      if (code == ASHIFTRT
+	  && !VECTOR_MODE_P (mode)
           && SUBREG_P (op0)
           && CONST_INT_P (op1)
-          && (GET_CODE (SUBREG_REG (op0)) == LSHIFTRT)
+	  && GET_CODE (SUBREG_REG (op0)) == LSHIFTRT
           && !VECTOR_MODE_P (GET_MODE (SUBREG_REG (op0)))
           && CONST_INT_P (XEXP (SUBREG_REG (op0), 1))
           && (GET_MODE_BITSIZE (GET_MODE (SUBREG_REG (op0)))
--- gcc/testsuite/gcc.c-torture/execute/pr63843.c.jj	2014-11-18 13:43:45.417544096 +0100
+++ gcc/testsuite/gcc.c-torture/execute/pr63843.c	2014-11-18 13:43:32.000000000 +0100
@@ -0,0 +1,31 @@
+/* PR rtl-optimization/63843 */
+
+static inline __attribute__ ((always_inline))
+unsigned short foo (unsigned short v)
+{
+  return (v << 8) | (v >> 8);
+}
+
+unsigned short __attribute__ ((noinline, noclone, hot))
+bar (unsigned char *x)
+{
+  unsigned int a;
+  unsigned short b;
+  __builtin_memcpy (&a, &x[0], sizeof (a));
+  a ^= 0x80808080U;
+  __builtin_memcpy (&x[0], &a, sizeof (a));
+  __builtin_memcpy (&b, &x[2], sizeof (b));
+  return foo (b);
+}
+
+int
+main ()
+{
+  unsigned char x[8] = { 0x01, 0x01, 0x01, 0x01 };
+  if (__CHAR_BIT__ == 8
+      && sizeof (short) == 2
+      && sizeof (int) == 4
+      && bar (x) != 0x8181U)
+    __builtin_abort ();
+  return 0;
+}

	Jakub

^ permalink raw reply	[flat|nested] 2+ messages in thread

* Re: [PATCH] Fix up r217118 - simplify_binary_operation_1 (PR rtl-optimization/63843)
  2014-11-18 22:08 [PATCH] Fix up r217118 - simplify_binary_operation_1 (PR rtl-optimization/63843) Jakub Jelinek
@ 2014-11-19  8:49 ` Richard Biener
  0 siblings, 0 replies; 2+ messages in thread
From: Richard Biener @ 2014-11-19  8:49 UTC (permalink / raw)
  To: Jakub Jelinek, Eric Botcazou; +Cc: gcc-patches

On November 18, 2014 10:59:28 PM CET, Jakub Jelinek <jakub@redhat.com> wrote:
>Hi!
>
>The case ASHIFTRT: which is meant for this optimization is preceeded by
>/* FALLTHRU */ from ROTATE cases, which can't be optimized this way.
>Thus, this patch limits this optimization to ASHIFTRT.
>
>Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk?

OK.

Thanks,
Richard.

>2014-11-18  Jakub Jelinek  <jakub@redhat.com>
>
>	PR rtl-optimization/63843
>	* simplify-rtx.c (simplify_binary_operation_1) <case ASHIFTRT>: For
>	optimization of ashiftrt of subreg of lshiftrt, check that code
>	is ASHIFTRT.
>
>	* gcc.c-torture/execute/pr63843.c: New test.
>
>--- gcc/simplify-rtx.c.jj	2014-11-18 10:17:01.000000000 +0100
>+++ gcc/simplify-rtx.c	2014-11-18 13:44:26.727792683 +0100
>@@ -3118,10 +3118,11 @@ simplify_binary_operation_1 (enum rtx_co
>          (subreg:M1 (ashiftrt:M2 (reg:M2)
>                                  (const_int <c1 + c2>))
>           <low_part>).  */
>-      if (!VECTOR_MODE_P (mode)
>+      if (code == ASHIFTRT
>+	  && !VECTOR_MODE_P (mode)
>           && SUBREG_P (op0)
>           && CONST_INT_P (op1)
>-          && (GET_CODE (SUBREG_REG (op0)) == LSHIFTRT)
>+	  && GET_CODE (SUBREG_REG (op0)) == LSHIFTRT
>           && !VECTOR_MODE_P (GET_MODE (SUBREG_REG (op0)))
>           && CONST_INT_P (XEXP (SUBREG_REG (op0), 1))
>           && (GET_MODE_BITSIZE (GET_MODE (SUBREG_REG (op0)))
>--- gcc/testsuite/gcc.c-torture/execute/pr63843.c.jj	2014-11-18
>13:43:45.417544096 +0100
>+++ gcc/testsuite/gcc.c-torture/execute/pr63843.c	2014-11-18
>13:43:32.000000000 +0100
>@@ -0,0 +1,31 @@
>+/* PR rtl-optimization/63843 */
>+
>+static inline __attribute__ ((always_inline))
>+unsigned short foo (unsigned short v)
>+{
>+  return (v << 8) | (v >> 8);
>+}
>+
>+unsigned short __attribute__ ((noinline, noclone, hot))
>+bar (unsigned char *x)
>+{
>+  unsigned int a;
>+  unsigned short b;
>+  __builtin_memcpy (&a, &x[0], sizeof (a));
>+  a ^= 0x80808080U;
>+  __builtin_memcpy (&x[0], &a, sizeof (a));
>+  __builtin_memcpy (&b, &x[2], sizeof (b));
>+  return foo (b);
>+}
>+
>+int
>+main ()
>+{
>+  unsigned char x[8] = { 0x01, 0x01, 0x01, 0x01 };
>+  if (__CHAR_BIT__ == 8
>+      && sizeof (short) == 2
>+      && sizeof (int) == 4
>+      && bar (x) != 0x8181U)
>+    __builtin_abort ();
>+  return 0;
>+}
>
>	Jakub


^ permalink raw reply	[flat|nested] 2+ messages in thread

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2014-11-18 22:08 [PATCH] Fix up r217118 - simplify_binary_operation_1 (PR rtl-optimization/63843) Jakub Jelinek
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