PR rtl-optimization/44659

	* combine.c (make_compound_operation) <SUBREG>: Do not return the
	result of force_to_mode if it partially re-expanded the compound.


git-svn-id: https://gcc.gnu.org/svn/gcc/trunk@161523 138bc75d-0d04-0410-961f-82ee72b054a4

9 files changed, 152 insertions, 21 deletions

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index c041e043dd9..7eeef8dfd08 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,7 +1,14 @@
+2010-06-29  Eric Botcazou  <ebotcazou@adacore.com>
+
+	PR rtl-optimization/44659
+	* combine.c (make_compound_operation) <SUBREG>: Do not return the
+	result of force_to_mode if it partially re-expanded the compound.
+
 2010-06-28  Jan Hubicka  <jh@suse.cz>
 
 	PR middle-end/44671
-	* ipa-split.c (test_nonssa_use, mark_nonssa_use): Check also uses of RESULT_DECL.
+	* ipa-split.c (test_nonssa_use, mark_nonssa_use): Check also uses of
+	RESULT_DECL.
 
 2010-06-28  Anatoly Sokolov  <aesok@post.ru>
 
@@ -22,7 +29,7 @@
 	fold_unary_loc, fold_negate_const, fold_abs_const, fold_not_const,
 	round_up_loc): Adjust call to force_fit_type_double.
 
-2010-06-28  Philipp Tomsich <philipp.tomsich@theobroma-systems.com>
+2010-06-28  Philipp Tomsich  <philipp.tomsich@theobroma-systems.com>
 
 	* config/rs6000/rs6000.h (PROCESSOR_TITAN): Declare.
 
@@ -62,7 +69,7 @@
 	* ipa-inline.c (add_new_edges_to_heap): Do not add edges to uninlinable
 	functions.
 
-2010-06-28  Philipp Tomsich <philipp.tomsich@theobroma-systems.com>
+2010-06-28  Philipp Tomsich  <philipp.tomsich@theobroma-systems.com>
 
 	* config.gcc (powerpc*-*-*): Handle titan.
 	* config/rs6000/rs6000.c (titan_cost): New costs.
@@ -104,7 +111,7 @@
 	* omp-low.c (maybe_catch_exception): Likewise.
 	* Makefile.in: Update dependencies.
 
-2010-06-28  Bingfeng Mei <bmei@broadcom.com>
+2010-06-28  Bingfeng Mei  <bmei@broadcom.com>
 
         * cgraph.h (struct varpool_node): new used_from_object_file flag.
         (struct cgraph_local_info): new used_from_object_file flag.
@@ -132,8 +139,8 @@
 
 	PR middle-end/44671
 	PR middle-end/44686
-	* tree.c (build_function_decl_skip_args): Clear DECL_BUILT_IN on signature
-	change.
+	* tree.c (build_function_decl_skip_args): Clear DECL_BUILT_IN on
+	signature change.
 	* ipa-split.c (split_function): Always clear DECL_BUILT_IN.
 	* ipa-prop.c (ipa_modify_formal_parameters): Likewise.
 
@@ -501,8 +508,8 @@
 	functions for dealing with three-operand statements.
 	* tree.c (commutative_ternary_tree_code): New function.
 	* tree.h (commutative_ternary_tree_code): Declare it.
-	* tree-vrp.c (gimple_assign_nonnegative_warnv_p): Return false for ternary
-	statements.
+	* tree-vrp.c (gimple_assign_nonnegative_warnv_p): Return false for
+	ternary statements.
 	(gimple_assign_nonzero_warnv_p): Likewise.
 	* tree-ssa-sccvn.c (stmt_has_constants): Handle GIMPLE_TERNARY_RHS.
 	* tree-ssa-ccp.c (get_rhs_assign_op_for_ccp): New static function.
@@ -3050,7 +3057,7 @@
 	* tree-inline.c (expand_call_inline): Pass translated return value of
 	cgraph_inline_failed_string to diagnostic function.
 
-2010-06-08  Andrew Pinski <pinskia@gmail.com>
+2010-06-08  Andrew Pinski  <pinskia@gmail.com>
 	    Shujing Zhao  <pearly.zhao@oracle.com>
 
 	PR c/37724
diff --git a/gcc/combine.c b/gcc/combine.c
index 1bee2c7f422..d3305cb4abe 100644
--- a/gcc/combine.c
+++ b/gcc/combine.c
@@ -7277,22 +7277,21 @@ make_compound_operation (rtx x, enum rtx_code in_code)
       /* Call ourselves recursively on the inner expression.  If we are
 	 narrowing the object and it has a different RTL code from
 	 what it originally did, do this SUBREG as a force_to_mode.  */
-
-      tem = make_compound_operation (SUBREG_REG (x), in_code);
-
       {
-	rtx simplified = simplify_subreg (mode, tem, GET_MODE (SUBREG_REG (x)),
-					  SUBREG_BYTE (x));
+	rtx inner = SUBREG_REG (x), simplified;
+	
+	tem = make_compound_operation (inner, in_code);
 
+	simplified
+	  = simplify_subreg (mode, tem, GET_MODE (inner), SUBREG_BYTE (x));
 	if (simplified)
 	  tem = simplified;
 
-	if (GET_CODE (tem) != GET_CODE (SUBREG_REG (x))
-	    && GET_MODE_SIZE (mode) < GET_MODE_SIZE (GET_MODE (SUBREG_REG (x)))
+	if (GET_CODE (tem) != GET_CODE (inner)
+	    && GET_MODE_SIZE (mode) < GET_MODE_SIZE (GET_MODE (inner))
 	    && subreg_lowpart_p (x))
 	  {
-	    rtx newer = force_to_mode (tem, mode, ~(HOST_WIDE_INT) 0,
-				       0);
+	    rtx newer = force_to_mode (tem, mode, ~(HOST_WIDE_INT) 0, 0);
 
 	    /* If we have something other than a SUBREG, we might have
 	       done an expansion, so rerun ourselves.  */
@@ -7300,9 +7299,16 @@ make_compound_operation (rtx x, enum rtx_code in_code)
 	      newer = make_compound_operation (newer, in_code);
 
 	    /* force_to_mode can expand compounds.  If it just re-expanded the
-	       compound use gen_lowpart instead to convert to the desired
-	       mode.  */
-	    if (rtx_equal_p (newer, x))
+	       compound, use gen_lowpart to convert to the desired mode.  */
+	    if (rtx_equal_p (newer, x)
+		/* Likewise if it re-expanded the compound only partially.
+		   This happens for SUBREG of ZERO_EXTRACT if they extract
+		   the same number of bits.  */
+		|| (GET_CODE (newer) == SUBREG
+		    && (GET_CODE (SUBREG_REG (newer)) == LSHIFTRT
+			|| GET_CODE (SUBREG_REG (newer)) == ASHIFTRT)
+		    && GET_CODE (inner) == AND
+		    && rtx_equal_p (SUBREG_REG (newer), XEXP (inner, 0))))
 	      return gen_lowpart (GET_MODE (x), tem);
 
 	    return newer;
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index e3558942969..958ddefc128 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,13 @@
+2010-06-29  H.J. Lu  <hongjiu.lu@intel.com>
+
+	PR rtl-optimization/44659
+	* gcc.target/i386/extract-1.c: New.
+	* gcc.target/i386/extract-2.c: Likewise.
+	* gcc.target/i386/extract-3.c: Likewise.
+	* gcc.target/i386/extract-4.c: Likewise.
+	* gcc.target/i386/extract-5.c: Likewise.
+	* gcc.target/i386/extract-6.c: Likewise.
+
 2010-06-28  Jakub Jelinek  <jakub@redhat.com>
 
 	PR c++/44682
diff --git a/gcc/testsuite/gcc.target/i386/extract-1.c b/gcc/testsuite/gcc.target/i386/extract-1.c
new file mode 100644
index 00000000000..102beb230ac
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/extract-1.c
@@ -0,0 +1,10 @@
+/* { dg-do compile } */
+/* { dg-options "-O2 -mtune=generic" } */
+
+int
+foo (unsigned char x, unsigned char y)
+{
+   return (x % y) != 0;
+}
+
+/* { dg-final { scan-assembler-not "test\[b\]?\[^\\n\]*%\[a-d\]l" } } */
diff --git a/gcc/testsuite/gcc.target/i386/extract-2.c b/gcc/testsuite/gcc.target/i386/extract-2.c
new file mode 100644
index 00000000000..3bb5f154c4e
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/extract-2.c
@@ -0,0 +1,11 @@
+/* { dg-do compile } */
+/* { dg-options "-O2 -mtune=generic" } */
+
+int
+foo (unsigned char x, unsigned char y)
+{
+   return (x % y) > 4;
+}
+
+/* { dg-final { scan-assembler-times "cmp\[b\]?\[^\\n\]*%\[a-d\]h" 1 } } */
+/* { dg-final { scan-assembler-not "cmp\[b\]?\[^\\n\]*%\[a-d\]l" } } */
diff --git a/gcc/testsuite/gcc.target/i386/extract-3.c b/gcc/testsuite/gcc.target/i386/extract-3.c
new file mode 100644
index 00000000000..520bf3bb557
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/extract-3.c
@@ -0,0 +1,21 @@
+/* { dg-do compile } */
+/* { dg-options "-O2 -mtune=generic" } */
+
+typedef struct
+{
+  unsigned char c1;
+  unsigned char c2;
+  unsigned char c3;
+  unsigned char c4;
+} foo_t;
+
+int
+#ifndef __x86_64__
+__attribute__((regparm(3)))
+#endif
+foo (foo_t x)
+{
+   return x.c2 != 0;
+}
+
+/* { dg-final { scan-assembler-not "test\[b\]?\[^\\n\]*%\[a-z0-9\]+l" } } */
diff --git a/gcc/testsuite/gcc.target/i386/extract-4.c b/gcc/testsuite/gcc.target/i386/extract-4.c
new file mode 100644
index 00000000000..716ae2299ea
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/extract-4.c
@@ -0,0 +1,22 @@
+/* { dg-do compile } */
+/* { dg-options "-O2 -mtune=generic" } */
+
+typedef struct
+{
+  unsigned char c1;
+  unsigned char c2;
+  unsigned char c3;
+  unsigned char c4;
+} foo_t;
+
+int
+#ifndef __x86_64__
+__attribute__((regparm(3)))
+#endif
+foo (foo_t x)
+{
+   return x.c2 > 4;
+}
+
+/* { dg-final { scan-assembler-times "cmp\[b\]?\[^\\n\]*%\[a-z0-9\]+h" 1 } } */
+/* { dg-final { scan-assembler-not "cmp\[b\]?\[^\\n\]*%\[a-z0-9\]+l" } } */
diff --git a/gcc/testsuite/gcc.target/i386/extract-5.c b/gcc/testsuite/gcc.target/i386/extract-5.c
new file mode 100644
index 00000000000..a488dafa20f
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/extract-5.c
@@ -0,0 +1,21 @@
+/* { dg-do compile } */
+/* { dg-options "-O2 -mtune=generic" } */
+
+typedef struct
+{
+  unsigned int c1:8;
+  unsigned int c2:8;
+  unsigned int c3:8;
+  unsigned int c4:8;
+} foo_t;
+
+int
+#ifndef __x86_64__
+__attribute__((regparm(3)))
+#endif
+foo (foo_t x)
+{
+   return x.c2 != 0;
+}
+
+/* { dg-final { scan-assembler-not "test\[b\]?\[^\\n\]*%\[a-z0-9\]+l" } } */
diff --git a/gcc/testsuite/gcc.target/i386/extract-6.c b/gcc/testsuite/gcc.target/i386/extract-6.c
new file mode 100644
index 00000000000..1440ec3be35
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/extract-6.c
@@ -0,0 +1,23 @@
+/* { dg-do compile } */
+/* { dg-options "-O2 -mtune=generic" } */
+
+typedef struct
+{
+  unsigned int c1:8;
+  unsigned int c2:8;
+  unsigned int c3:8;
+  unsigned int c4:8;
+
+} foo_t;
+
+int
+#ifndef __x86_64__
+__attribute__((regparm(3)))
+#endif
+foo (foo_t x)
+{
+   return x.c2 > 4;
+}
+
+/* { dg-final { scan-assembler-times "cmp\[b\]?\[^\\n\]*%\[a-z0-9\]+h" 1 } } */
+/* { dg-final { scan-assembler-not "cmp\[b\]?\[^\\n\]*%\[a-z0-9\]+l" } } */