re PR tree-optimization/55177 (missed optimizations with __builtin_bswap)

	PR rtl-optimization/55177
	* simplify-rtx.c (simplify_unary_operation_1) <NOT>: Deal with BSWAP.
	(simplify_byte_swapping_operation): New.
	(simplify_binary_operation_1): Call it for AND, IOR and XOR.
	(simplify_relational_operation_1): Deal with BSWAP.

From-SVN: r199278

7 files changed, 247 insertions, 2 deletions

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 51e7b9e..ae1d9b5 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,11 @@
+2013-05-24  Eric Botcazou  <ebotcazou@adacore.com>
+
+	PR rtl-optimization/55177
+	* simplify-rtx.c (simplify_unary_operation_1) <NOT>: Deal with BSWAP.
+	(simplify_byte_swapping_operation): New.
+	(simplify_binary_operation_1): Call it for AND, IOR and XOR.
+	(simplify_relational_operation_1): Deal with BSWAP.
+
 2013-05-23  Richard Henderson  <rth@redhat.com>
 
 	PR target/56742
diff --git a/gcc/simplify-rtx.c b/gcc/simplify-rtx.c
index 865d37d..5c1dd25 100644
--- a/gcc/simplify-rtx.c
+++ b/gcc/simplify-rtx.c
@@ -858,7 +858,6 @@ simplify_unary_operation_1 (enum rtx_code code, enum machine_mode mode, rtx op)
       /* (not (ashiftrt foo C)) where C is the number of bits in FOO
 	 minus 1 is (ge foo (const_int 0)) if STORE_FLAG_VALUE is -1,
 	 so we can perform the above simplification.  */
-
       if (STORE_FLAG_VALUE == -1
 	  && GET_CODE (op) == ASHIFTRT
 	  && GET_CODE (XEXP (op, 1))
@@ -890,7 +889,6 @@ simplify_unary_operation_1 (enum rtx_code code, enum machine_mode mode, rtx op)
 	 with negating logical insns (and-not, nand, etc.).  If result has
 	 only one NOT, put it first, since that is how the patterns are
 	 coded.  */
-
       if (GET_CODE (op) == IOR || GET_CODE (op) == AND)
 	{
 	  rtx in1 = XEXP (op, 0), in2 = XEXP (op, 1);
@@ -913,6 +911,13 @@ simplify_unary_operation_1 (enum rtx_code code, enum machine_mode mode, rtx op)
 	  return gen_rtx_fmt_ee (GET_CODE (op) == IOR ? AND : IOR,
 				 mode, in1, in2);
 	}
+
+      /* (not (bswap x)) -> (bswap (not x)).  */
+      if (GET_CODE (op) == BSWAP)
+	{
+	  rtx x = simplify_gen_unary (NOT, mode, XEXP (op, 0), mode);
+	  return simplify_gen_unary (BSWAP, mode, x, mode);
+	}
       break;
 
     case NEG:
@@ -2050,6 +2055,36 @@ simplify_const_unary_operation (enum rtx_code code, enum machine_mode mode,
   return NULL_RTX;
 }
 
+/* Subroutine of simplify_binary_operation to simplify a binary operation
+   CODE that can commute with byte swapping, with result mode MODE and
+   operating on OP0 and OP1.  CODE is currently one of AND, IOR or XOR.
+   Return zero if no simplification or canonicalization is possible.  */
+
+static rtx
+simplify_byte_swapping_operation (enum rtx_code code, enum machine_mode mode,
+				  rtx op0, rtx op1)
+{
+  rtx tem;
+
+  /* (op (bswap x) C1)) -> (bswap (op x C2)) with C2 swapped.  */
+  if (GET_CODE (op0) == BSWAP
+      && (CONST_INT_P (op1) || CONST_DOUBLE_AS_INT_P (op1)))
+    {
+      tem = simplify_gen_binary (code, mode, XEXP (op0, 0),
+				 simplify_gen_unary (BSWAP, mode, op1, mode));
+      return simplify_gen_unary (BSWAP, mode, tem, mode);
+    }
+
+  /* (op (bswap x) (bswap y)) -> (bswap (op x y)).  */
+  if (GET_CODE (op0) == BSWAP && GET_CODE (op1) == BSWAP)
+    {
+      tem = simplify_gen_binary (code, mode, XEXP (op0, 0), XEXP (op1, 0));
+      return simplify_gen_unary (BSWAP, mode, tem, mode);
+    }
+
+  return NULL_RTX;
+}
+
 /* Subroutine of simplify_binary_operation to simplify a commutative,
    associative binary operation CODE with result mode MODE, operating
    on OP0 and OP1.  CODE is currently one of PLUS, MULT, AND, IOR, XOR,
@@ -2791,6 +2826,10 @@ simplify_binary_operation_1 (enum rtx_code code, enum machine_mode mode,
 					XEXP (op0, 1));
         }
 
+      tem = simplify_byte_swapping_operation (code, mode, op0, op1);
+      if (tem)
+	return tem;
+
       tem = simplify_associative_operation (code, mode, op0, op1);
       if (tem)
 	return tem;
@@ -2934,6 +2973,10 @@ simplify_binary_operation_1 (enum rtx_code code, enum machine_mode mode,
 	  && (reversed = reversed_comparison (op0, mode)))
 	return reversed;
 
+      tem = simplify_byte_swapping_operation (code, mode, op0, op1);
+      if (tem)
+	return tem;
+
       tem = simplify_associative_operation (code, mode, op0, op1);
       if (tem)
 	return tem;
@@ -3116,6 +3159,10 @@ simplify_binary_operation_1 (enum rtx_code code, enum machine_mode mode,
 	  && op1 == XEXP (XEXP (op0, 0), 0))
 	return simplify_gen_binary (AND, mode, op1, XEXP (op0, 1));
 
+      tem = simplify_byte_swapping_operation (code, mode, op0, op1);
+      if (tem)
+	return tem;
+
       tem = simplify_associative_operation (code, mode, op0, op1);
       if (tem)
 	return tem;
@@ -4764,6 +4811,21 @@ simplify_relational_operation_1 (enum rtx_code code, enum machine_mode mode,
 				    simplify_gen_binary (XOR, cmp_mode,
 							 XEXP (op0, 1), op1));
 
+  /* (eq/ne (bswap x) C1) simplifies to (eq/ne x C2) with C2 swapped.  */
+  if ((code == EQ || code == NE)
+      && GET_CODE (op0) == BSWAP
+      && (CONST_INT_P (op1) || CONST_DOUBLE_AS_INT_P (op1)))
+    return simplify_gen_relational (code, mode, cmp_mode, XEXP (op0, 0),
+				    simplify_gen_unary (BSWAP, cmp_mode,
+							op1, cmp_mode));
+
+  /* (eq/ne (bswap x) (bswap y)) simplifies to (eq/ne x y).  */
+  if ((code == EQ || code == NE)
+      && GET_CODE (op0) == BSWAP
+      && GET_CODE (op1) == BSWAP)
+    return simplify_gen_relational (code, mode, cmp_mode,
+				    XEXP (op0, 0), XEXP (op1, 0));
+
   if (op0code == POPCOUNT && op1 == const0_rtx)
     switch (code)
       {
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index b1895fb..521873c 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,10 @@
+2013-05-24  Eric Botcazou  <ebotcazou@adacore.com>
+
+	* gcc.dg/builtin-bswap-6.c: New test.
+	* gcc.dg/builtin-bswap-7.c: Likewise.
+	* gcc.dg/builtin-bswap-8.c: Likewise.
+	* gcc.dg/builtin-bswap-9.c: Likewise.
+
 2013-05-23  Christian Bruel  <christian.bruel@st.com>
 
 	PR debug/57351
diff --git a/gcc/testsuite/gcc.dg/builtin-bswap-6.c b/gcc/testsuite/gcc.dg/builtin-bswap-6.c
new file mode 100644
index 0000000..544f26e
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/builtin-bswap-6.c
@@ -0,0 +1,38 @@
+/* { dg-do compile { target arm*-*-* alpha*-*-* ia64*-*-* x86_64-*-* s390x-*-* powerpc*-*-* rs6000-*-* } } */
+/* { dg-require-effective-target stdint_types } */
+/* { dg-options "-O -fdump-rtl-combine" } */
+
+#include <stdint.h>
+
+#define BS(X) __builtin_bswap32(X)
+
+int foo1 (uint32_t a)
+{
+  if (BS (a) == 0xA0000)
+    return 1;
+  return 0;
+}
+
+int foo2 (uint32_t a)
+{
+  if (BS (a) != 0xA0000)
+    return 1;
+  return 0;
+}
+
+int foo3 (uint32_t a, uint32_t b)
+{
+  if (BS (a) == BS (b))
+    return 1;
+  return 0;
+}
+
+int foo4 (uint32_t a, uint32_t b)
+{
+  if (BS (a) != BS (b))
+    return 1;
+  return 0;
+}
+
+/* { dg-final { scan-rtl-dump-not "bswapsi" "combine" } } */
+/* { dg-final { cleanup-rtl-dump "combine" } } */
diff --git a/gcc/testsuite/gcc.dg/builtin-bswap-7.c b/gcc/testsuite/gcc.dg/builtin-bswap-7.c
new file mode 100644
index 0000000..399b825
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/builtin-bswap-7.c
@@ -0,0 +1,39 @@
+/* { dg-do compile { target arm*-*-* alpha*-*-* ia64*-*-* x86_64-*-* s390x-*-* powerpc*-*-* rs6000-*-* } } */
+/* { dg-require-effective-target stdint_types } */
+/* { dg-require-effective-target lp64 } */
+/* { dg-options "-O -fdump-rtl-combine" } */
+
+#include <stdint.h>
+
+#define BS(X) __builtin_bswap64(X)
+
+int foo1 (uint64_t a)
+{
+  if (BS (a) == 0xA00000000)
+    return 1;
+  return 0;
+}
+
+int foo2 (uint64_t a)
+{
+  if (BS (a) != 0xA00000000)
+    return 1;
+  return 0;
+}
+
+int foo3 (uint64_t a, uint64_t b)
+{
+  if (BS (a) == BS (b))
+    return 1;
+  return 0;
+}
+
+int foo4 (uint64_t a, uint64_t b)
+{
+  if (BS (a) != BS (b))
+    return 1;
+  return 0;
+}
+
+/* { dg-final { scan-rtl-dump-not "bswapdi" "combine" } } */
+/* { dg-final { cleanup-rtl-dump "combine" } } */
diff --git a/gcc/testsuite/gcc.dg/builtin-bswap-8.c b/gcc/testsuite/gcc.dg/builtin-bswap-8.c
new file mode 100644
index 0000000..db75021
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/builtin-bswap-8.c
@@ -0,0 +1,45 @@
+/* { dg-do compile { target arm*-*-* alpha*-*-* ia64*-*-* x86_64-*-* s390x-*-* powerpc*-*-* rs6000-*-* } } */
+/* { dg-require-effective-target stdint_types } */
+/* { dg-options "-O -fdump-rtl-combine" } */
+
+#include <stdint.h>
+
+#define BS(X) __builtin_bswap32(X)
+
+uint32_t foo1 (uint32_t a)
+{
+  return BS (~ BS (a));
+}
+
+uint32_t foo2 (uint32_t a)
+{
+  return BS (BS (a) & 0xA0000);
+}
+
+uint32_t foo3 (uint32_t a)
+{
+  return BS (BS (a) | 0xA0000);
+}
+
+uint32_t foo4 (uint32_t a)
+{
+  return BS (BS (a) ^ 0xA0000);
+}
+
+uint32_t foo5 (uint32_t a, uint32_t b)
+{
+  return BS (BS (a) & BS (b));
+}
+
+uint32_t foo6 (uint32_t a, uint32_t b)
+{
+  return BS (BS (a) | BS (b));
+}
+
+uint32_t foo7 (uint32_t a, uint32_t b)
+{
+  return BS (BS (a) ^ BS (b));
+}
+
+/* { dg-final { scan-rtl-dump-not "bswapsi" "combine" } } */
+/* { dg-final { cleanup-rtl-dump "combine" } } */
diff --git a/gcc/testsuite/gcc.dg/builtin-bswap-9.c b/gcc/testsuite/gcc.dg/builtin-bswap-9.c
new file mode 100644
index 0000000..632dddf
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/builtin-bswap-9.c
@@ -0,0 +1,46 @@
+/* { dg-do compile { target arm*-*-* alpha*-*-* ia64*-*-* x86_64-*-* s390x-*-* powerpc*-*-* rs6000-*-* } } */
+/* { dg-require-effective-target stdint_types } */
+/* { dg-require-effective-target lp64 } */
+/* { dg-options "-O -fdump-rtl-combine" } */
+
+#include <stdint.h>
+
+#define BS(X) __builtin_bswap64(X)
+
+uint64_t foo1 (uint64_t a)
+{
+  return BS (~ BS (a));
+}
+
+uint64_t foo2 (uint64_t a)
+{
+  return BS (BS (a) & 0xA00000000);
+}
+
+uint64_t foo3 (uint64_t a)
+{
+  return BS (BS (a) | 0xA00000000);
+}
+
+uint64_t foo4 (uint64_t a)
+{
+  return BS (BS (a) ^ 0xA00000000);
+}
+
+uint64_t foo5 (uint64_t a, uint64_t b)
+{
+  return BS (BS (a) & BS (b));
+}
+
+uint64_t foo6 (uint64_t a, uint64_t b)
+{
+  return BS (BS (a) | BS (b));
+}
+
+uint64_t foo7 (uint64_t a, uint64_t b)
+{
+  return BS (BS (a) ^ BS (b));
+}
+
+/* { dg-final { scan-rtl-dump-not "bswapdi" "combine" } } */
+/* { dg-final { cleanup-rtl-dump "combine" } } */