re PR tree-optimization/72517 (436.cactusADM: More than 40% regression in O3 and…

re PR tree-optimization/72517 (436.cactusADM: More than 40% regression in O3 and Ofast on AMD bdver4 m/c.)

2016-07-26  Richard Biener  <rguenther@suse.de>

	PR middle-end/72517
	* expmed.c (extract_bit_field_1): Constrain the vector mode
	with element size matching the extraction mode size when
	choosing a better vector mode to do the extraction from.

From-SVN: r238756

gcc/ChangeLog

 2016-07-26  Richard Biener  <rguenther@suse.de>
+
+	PR middle-end/72517
+	* expmed.c (extract_bit_field_1): Constrain the vector mode
+	with element size matching the extraction mode size when
+	choosing a better vector mode to do the extraction from.
+
+2016-07-26  Richard Biener  <rguenther@suse.de>
 	    Prathamesh Kulkarni <prathamesh.kulkarni@linaro.org>
 
 	PR middle-end/70920

gcc/expmed.c

@@ -1581,6 +1581,7 @@ extract_bit_field_1 (rtx str_rtx, unsigned HOST_WIDE_INT bitsize,
 
       for (; new_mode != VOIDmode ; new_mode = GET_MODE_WIDER_MODE (new_mode))
 	if (GET_MODE_SIZE (new_mode) == GET_MODE_SIZE (GET_MODE (op0))
+	    && GET_MODE_UNIT_SIZE (new_mode) == GET_MODE_SIZE (tmode)
 	    && targetm.vector_mode_supported_p (new_mode))
 	  break;
       if (new_mode != VOIDmode)