From 2ee68beee709e48fce85b8892ff9985acc6a91a8 Mon Sep 17 00:00:00 2001
From: Pat Haugen <pthaugen@linux.ibm.com>
Date: Tue, 17 May 2022 15:53:24 -0500
Subject: Fix register count when not splitting Complex IEEE 128-bit args.

For ABI_V4, we do not split complex args. This created a problem because
even though an arg would be passed in two VSX regs, we were only advancing the
function arg counter by one VSX register. Fixed with this patch.

	PR target/99685

gcc/
	* config/rs6000/rs6000-call.cc (rs6000_function_arg_advance_1): Bump
	register count when not splitting IEEE 128-bit Complex.

diff --git a/gcc/config/rs6000/rs6000-call.cc b/gcc/config/rs6000/rs6000-call.cc
index 6011fe8..551968b 100644
--- a/gcc/config/rs6000/rs6000-call.cc
+++ b/gcc/config/rs6000/rs6000-call.cc
@@ -1111,6 +1111,12 @@ rs6000_function_arg_advance_1 (CUMULATIVE_ARGS *cum, machine_mode mode,
 	{
 	  cum->vregno += n_elts;
 
+	  /* If we are not splitting Complex IEEE128 args then account for the
+	     fact that they are passed in 2 VSX regs. */
+	  if (!targetm.calls.split_complex_arg && type
+	      && TREE_CODE (type) == COMPLEX_TYPE && elt_mode == KCmode)
+	    cum->vregno++;
+
 	  if (!TARGET_ALTIVEC)
 	    error ("cannot pass argument in vector register because"
 		   " altivec instructions are disabled, use %qs"
-- 
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