Remove global call sets: loop-iv.c

Similar idea to the combine.c and gcse.c patches.

2019-09-30  Richard Sandiford  <richard.sandiford@arm.com>

gcc/
	* loop-iv.c: Include regs.h and function-abi.h.
	(simplify_using_initial_values): Use insn_callee_abi to get the
	ABI of the call insn target.  Conservatively assume that
	partially-clobbered registers are altered.

From-SVN: r276326

gcc/ChangeLog

 2019-09-30  Richard Sandiford  <richard.sandiford@arm.com>
 
+	* loop-iv.c: Include regs.h and function-abi.h.
+	(simplify_using_initial_values): Use insn_callee_abi to get the
+	ABI of the call insn target.  Conservatively assume that
+	partially-clobbered registers are altered.
+
+2019-09-30  Richard Sandiford  <richard.sandiford@arm.com>
+
 	* function-abi.h (call_clobbers_in_region): Declare.
 	(call_clobbered_in_region_p): New function.
 	* function-abi.cc (call_clobbers_in_region): Likewise.

gcc/loop-iv.c

@@ -62,6 +62,8 @@ along with GCC; see the file COPYING3.  If not see
 #include "dumpfile.h"
 #include "rtl-iter.h"
 #include "tree-ssa-loop-niter.h"
+#include "regs.h"
+#include "function-abi.h"
 
 /* Possible return values of iv_get_reaching_def.  */
 
@@ -1972,8 +1974,14 @@ simplify_using_initial_values (class loop *loop, enum rtx_code op, rtx *expr)
 	  CLEAR_REG_SET (this_altered);
 	  note_stores (insn, mark_altered, this_altered);
 	  if (CALL_P (insn))
-	    /* Kill all call clobbered registers.  */
-	    IOR_REG_SET_HRS (this_altered, regs_invalidated_by_call);
+	    {
+	      /* Kill all registers that might be clobbered by the call.
+		 We don't track modes of hard registers, so we need to be
+		 conservative and assume that partial kills are full kills.  */
+	      function_abi callee_abi = insn_callee_abi (insn);
+	      IOR_REG_SET_HRS (this_altered,
+			       callee_abi.full_and_partial_reg_clobbers ());
+	    }
 
 	  if (suitable_set_for_replacement (insn, &dest, &src))
 	    {