PR 16522

Fix RSQRT.S instruction, add test case.

3 files changed, 197 insertions, 0 deletions

diff --git a/sim/mips/ChangeLog b/sim/mips/ChangeLog
index 4b05f8a..245053b 100644
--- a/sim/mips/ChangeLog
+++ b/sim/mips/ChangeLog
@@ -1,3 +1,17 @@
+start-sanitize-r5900
+Thu Nov  5 19:40:12 1998  Andrew Cagney  <cagney@b1.cygnus.com>
+
+	* r5900.igen (DIV): Do not clear clear SO/SU when already set.
+
+	* r5900.igen (RSQRT.S): Do not compute 1/srqt(abs(T)) when T
+ 	negative, compute S/sqrt(abs(T)) instead.  Correctly set FCSR
+ 	bits.
+
+	* r5900.igen (RSQRT.S): Handle overflow/underflow better. Check
+ 	sign of FT not FS.
+	(r59fp_store): Clarify "bad value" abort messages.
+
+end-sanitize-r5900
 start-sanitize-tx3904
 Sat Oct 30 09:49:10 1998  Frank Ch. Eigler  <fche@cygnus.com>
 
diff --git a/sim/testsuite/mips64r5900-elf/ChangeLog b/sim/testsuite/mips64r5900-elf/ChangeLog
index c9c920b..1c9111e 100644
--- a/sim/testsuite/mips64r5900-elf/ChangeLog
+++ b/sim/testsuite/mips64r5900-elf/ChangeLog
@@ -1,3 +1,7 @@
+Thu Nov  5 20:22:21 1998  Andrew Cagney  <cagney@b1.cygnus.com>
+
+	* f-rsqrt.s: Add tests for 0/sqrt(0) etc.
+
 Thu Oct 29 12:07:06 1998  Frank Ch. Eigler  <fche@cygnus.com>
 
 	* t-psrlvw.s (test_psrlvw): Add test for sign-extension in insn.
diff --git a/sim/testsuite/mips64r5900-elf/f-rsqrt.s b/sim/testsuite/mips64r5900-elf/f-rsqrt.s
new file mode 100644
index 0000000..feb3454
--- /dev/null
+++ b/sim/testsuite/mips64r5900-elf/f-rsqrt.s
@@ -0,0 +1,179 @@
+.include "t-macros.i"
+
+	start
+
+	### $f3 = $f2 / sqrt ($f1)
+
+test_rsqrt:	
+	loadfp $f1 4.0
+	loadfp $f2 1.0
+	rsqrt.s $f3, $f2, $f1
+	checkfp 0 $f3 0.5
+
+	################
+
+ 
+##        +1.0 / sqrt (+0.0)
+##                -> 0x7fffffff (+Max) D+SD
+test_rsqrt_1:
+	clearfcsr
+	loadfp $f1, +1.0
+	loadfp $f2, +0.0
+	rsqrt.s $f3, $f1, $f2
+	checkfpx 1 0x00010021 $f3 0x7fffffff
+
+
+##        -1.0 / sqrt (+0.0)
+##                -> 0xffffffff (-Max) D+SD
+test_rsqrt_2:
+	clearfcsr
+	loadfp $f1, -1.0
+	loadfp $f2, +0.0
+	rsqrt.s $f3, $f1, $f2
+	checkfpx 1 0x00010021 $f3 0xffffffff
+
+
+##       0 / sqrt (-0)
+##and    0 / sqrt (0)
+##                ->0x7fffffff  I + SI
+test_rsqrt_3a:
+	clearfcsr
+	loadfp $f1, +0.0
+	loadfp $f2, -0.0
+	rsqrt.s $f3, $f1, $f2
+	checkfpx 1 0x00020041 $f3 0x7fffffff
+
+test_rsqrt_3b:
+	clearfcsr
+	loadfp $f1, +0.0
+	loadfp $f2, +0.0
+	rsqrt.s $f3, $f1, $f2
+	checkfpx 1 0x00020041 $f3 0x7fffffff
+
+
+##        Correctly:
+##                (-0) / sqrt (-0)
+##                        ->FFFFFFFF (I + SI)
+test_rsqrt_4a:
+	clearfcsr
+	loadfp $f1, -0.0
+	loadfp $f2, -0.0
+	rsqrt.s $f3, $f1, $f2
+	checkfpx 1 0x00020041 $f3 0xffffffff
+
+test_rsqrt_4b:
+	clearfcsr
+	loadfp $f1, -0.0
+	loadfp $f2, +0.0
+	rsqrt.s $f3, $f1, $f2
+	checkfpx 1 0x00020041 $f3 0xffffffff
+
+
+##	(max) / sqrt (min*2) -> no O+SO
+##
+test_rsqrt_5aa:
+	clearfcsr
+	loadfpx $f1, 0x7fffffff
+	loadfpx $f2, 0x00800001
+	rsqrt.s $f3, $f1, $f2
+	checkfpx 1 0x00000001 $f3 0x7fffffff
+
+test_rsqrt_5ab:
+	clearfcsr
+	loadfpx $f1, 0x7fffffff
+	loadfpx $f2, 0x80800001
+	rsqrt.s $f3, $f1, $f2
+	checkfpx 1 0x00020041 $f3 0x7fffffff
+
+test_rsqrt_5ba:
+	clearfcsr
+	loadfpx $f1, 0xffffffff
+	loadfpx $f2, 0x00800001
+	rsqrt.s $f3, $f1, $f2
+	checkfpx 1 0x00000001 $f3 0xffffffff
+
+test_rsqrt_5bb:
+	clearfcsr
+	loadfpx $f1, 0xffffffff
+	loadfpx $f2, 0x80800001
+	rsqrt.s $f3, $f1, $f2
+	checkfpx 1 0x00020041 $f3 0xffffffff
+
+	
+##	(max) / sqrt (min*2) -> no U+SU
+##
+test_rsqrt_6aa:
+	clearfcsr
+	loadfpx $f1, 0x00800001
+	loadfpx $f2, 0x7fffffff
+	rsqrt.s $f3, $f1, $f2
+	checkfpx 1 0x00000001 $f3 0x00000000
+
+test_rsqrt_6ab:
+	clearfcsr
+	loadfpx $f1, 0x00800001
+	loadfpx $f2, 0xffffffff
+	rsqrt.s $f3, $f1, $f2
+	checkfpx 1 0x00020041 $f3 0x00000000
+
+test_rsqrt_6ba:
+	clearfcsr
+	loadfpx $f1, 0x80800001
+	loadfpx $f2, 0x7fffffff
+	rsqrt.s $f3, $f1, $f2
+	checkfpx 1 0x00000001 $f3 0x80000000
+
+test_rsqrt_6bb:
+	clearfcsr
+	loadfpx $f1, 0x80800001
+	loadfpx $f2, 0xffffffff
+	rsqrt.s $f3, $f1, $f2
+	checkfpx 1 0x00020041 $f3 0x80000000
+
+
+##        Correctly:
+##                (max/min) / sqrt ([+-]0)
+##                        ->MAX/MIN (D + SD)
+test_rsqrt_7aa:
+	clearfcsr
+	loadfpx $f1, 0x7fffffff
+	loadfpx $f2, 0x00000000
+	rsqrt.s $f3, $f1, $f2
+	checkfpx 1 0x00010021 $f3 0x7fffffff
+
+test_rsqrt_7ab:
+	clearfcsr
+	loadfpx $f1, 0x7fffffff
+	loadfpx $f2, 0x80000000
+	rsqrt.s $f3, $f1, $f2
+	checkfpx 1 0x00010021 $f3 0x7fffffff
+
+test_rsqrt_7ba:
+	clearfcsr
+	loadfpx $f1, 0xffffffff
+	loadfpx $f2, 0x00000000
+	rsqrt.s $f3, $f1, $f2
+	checkfpx 1 0x00010021 $f3 0xffffffff
+
+test_rsqrt_7bb:
+	clearfcsr
+	loadfpx $f1, 0xffffffff
+	loadfpx $f2, 0x80000000
+	rsqrt.s $f3, $f1, $f2
+	checkfpx 1 0x00010021 $f3 0xffffffff
+
+	
+##	Like max/sqrt but check that bits are set/cleared
+##
+test_rsqrt_9aa:
+	clearfcsr
+	loadfpx $f1, 0x7fffffff
+	loadfpx $f2, 0x00000000
+	rsqrt.s $f3, $f1, $f2
+	loadfpx $f1, 0x00800001
+	loadfpx $f2, 0xffffffff
+	rsqrt.s $f3, $f1, $f2
+	checkfpx 1 0x00020061 $f3 0x00000000
+
+
+	exit0