[AArch64] Fix -mlow-precision-div (PR 86838)
Richard Sandiford
richard.sandiford@arm.com
Fri Aug 3 15:34:00 GMT 2018
The "@" handling broke -mlow-precision-div, because the scalar forms of
the instruction were provided by a pattern that also provided FRECPX
(and so were parameterised on an unspec code as well as a mode),
while the SIMD versions had a dedicated FRECPE pattern. This patch
moves the scalar FRECPE handling to the SIMD pattern too (as for FRECPS)
and uses a separate pattern for FRECPX.
The convention in aarch64-simd-builtins.def seemed to be to add
comments only if the mapping wasn't obvious (i.e. not just sticking
"aarch64_" on the beginning and "<mode>" on the end), so the patch
deletes the reference to the combined pattern instead of rewording it.
There didn't seem to be any coverage of -mlow-precision-div in the
testsuite, so the patch adds some tests for it.
Tested on aarch64-linux-gnu. OK to install?
Richard
2018-08-03 Richard Sandiford <richard.sandiford@arm.com>
gcc/
PR target/86838
* config/aarch64/iterators.md (FRECP, frecp_suffix): Delete.
* config/aarch64/aarch64-simd.md
(aarch64_frecp<FRECP:frecp_suffix><mode>): Fold FRECPE into...
(@aarch64_frecpe<mode>): ...here and the move FRECPX to...
(aarch64_frecpx<mode>): ...this new pattern.
* config/aarch64/aarch64-simd-builtins.def: Remove comment
about aarch64_frecp<FRECP:frecp_suffix><mode>.
gcc/testsuite/
PR target/86838
* gcc.target/aarch64/frecpe_1.c: New test.
* gcc.target/aarch64/frecpe_2.c: Likewise.
Index: gcc/config/aarch64/iterators.md
===================================================================
--- gcc/config/aarch64/iterators.md 2018-07-31 19:10:15.744291661 +0100
+++ gcc/config/aarch64/iterators.md 2018-08-03 16:32:07.531492221 +0100
@@ -1537,8 +1537,6 @@ (define_int_iterator FCVT [UNSPEC_FRINTZ
(define_int_iterator FCVT_F2FIXED [UNSPEC_FCVTZS UNSPEC_FCVTZU])
(define_int_iterator FCVT_FIXED2F [UNSPEC_SCVTF UNSPEC_UCVTF])
-(define_int_iterator FRECP [UNSPEC_FRECPE UNSPEC_FRECPX])
-
(define_int_iterator CRC [UNSPEC_CRC32B UNSPEC_CRC32H UNSPEC_CRC32W
UNSPEC_CRC32X UNSPEC_CRC32CB UNSPEC_CRC32CH
UNSPEC_CRC32CW UNSPEC_CRC32CX])
@@ -1788,8 +1786,6 @@ (define_int_attr hi_lanes_optab [(UNSPEC
(UNSPEC_UNPACKSLO "BYTES_BIG_ENDIAN")
(UNSPEC_UNPACKULO "BYTES_BIG_ENDIAN")])
-(define_int_attr frecp_suffix [(UNSPEC_FRECPE "e") (UNSPEC_FRECPX "x")])
-
(define_int_attr crc_variant [(UNSPEC_CRC32B "crc32b") (UNSPEC_CRC32H "crc32h")
(UNSPEC_CRC32W "crc32w") (UNSPEC_CRC32X "crc32x")
(UNSPEC_CRC32CB "crc32cb") (UNSPEC_CRC32CH "crc32ch")
Index: gcc/config/aarch64/aarch64-simd.md
===================================================================
--- gcc/config/aarch64/aarch64-simd.md 2018-08-02 11:59:06.851355923 +0100
+++ gcc/config/aarch64/aarch64-simd.md 2018-08-03 16:32:07.531492221 +0100
@@ -5879,21 +5879,22 @@ (define_insn "aarch64_simd_ld1<mode>_x2"
(define_insn "@aarch64_frecpe<mode>"
- [(set (match_operand:VHSDF 0 "register_operand" "=w")
- (unspec:VHSDF [(match_operand:VHSDF 1 "register_operand" "w")]
+ [(set (match_operand:VHSDF_HSDF 0 "register_operand" "=w")
+ (unspec:VHSDF_HSDF
+ [(match_operand:VHSDF_HSDF 1 "register_operand" "w")]
UNSPEC_FRECPE))]
"TARGET_SIMD"
- "frecpe\\t%0.<Vtype>, %1.<Vtype>"
+ "frecpe\t%<v>0<Vmtype>, %<v>1<Vmtype>"
[(set_attr "type" "neon_fp_recpe_<stype><q>")]
)
-(define_insn "aarch64_frecp<FRECP:frecp_suffix><mode>"
+(define_insn "aarch64_frecpx<mode>"
[(set (match_operand:GPF_F16 0 "register_operand" "=w")
(unspec:GPF_F16 [(match_operand:GPF_F16 1 "register_operand" "w")]
- FRECP))]
+ UNSPEC_FRECPX))]
"TARGET_SIMD"
- "frecp<FRECP:frecp_suffix>\\t%<s>0, %<s>1"
- [(set_attr "type" "neon_fp_recp<FRECP:frecp_suffix>_<GPF_F16:stype>")]
+ "frecpx\t%<s>0, %<s>1"
+ [(set_attr "type" "neon_fp_recpx_<GPF_F16:stype>")]
)
(define_insn "@aarch64_frecps<mode>"
Index: gcc/config/aarch64/aarch64-simd-builtins.def
===================================================================
--- gcc/config/aarch64/aarch64-simd-builtins.def 2018-06-14 12:27:40.672026808 +0100
+++ gcc/config/aarch64/aarch64-simd-builtins.def 2018-08-03 16:32:07.531492221 +0100
@@ -413,8 +413,6 @@
BUILTIN_VALL (BINOP, trn1, 0)
BUILTIN_VALL (BINOP, trn2, 0)
- /* Implemented by
- aarch64_frecp<FRECP:frecp_suffix><mode>. */
BUILTIN_GPF_F16 (UNOP, frecpe, 0)
BUILTIN_GPF_F16 (UNOP, frecpx, 0)
Index: gcc/testsuite/gcc.target/aarch64/frecpe_1.c
===================================================================
--- /dev/null 2018-07-26 10:26:13.137955424 +0100
+++ gcc/testsuite/gcc.target/aarch64/frecpe_1.c 2018-08-03 16:32:07.531492221 +0100
@@ -0,0 +1,18 @@
+/* { dg-options "-Ofast -mlow-precision-div" } */
+/* { dg-do compile } */
+
+float
+f1 (float x)
+{
+ return 1 / x;
+}
+
+/* { dg-final { scan-assembler {\tfrecpe\t(s[0-9]+), s0\n\tfrecps\t(s[0-9]+), \1, s0\n\tfmul\ts0, \1, \2\n} } } */
+
+double
+f2 (double x)
+{
+ return 1 / x;
+}
+
+/* { dg-final { scan-assembler {\tfrecpe\t(d[0-9]+), d0\n\tfrecps\t(d[0-9]+), \1, d0\n\tfmul\t\1, \1, \2\n\tfrecps\t\2, \1, d0\n\tfmul\td0, \1, \2\n} } } */
Index: gcc/testsuite/gcc.target/aarch64/frecpe_2.c
===================================================================
--- /dev/null 2018-07-26 10:26:13.137955424 +0100
+++ gcc/testsuite/gcc.target/aarch64/frecpe_2.c 2018-08-03 16:32:07.531492221 +0100
@@ -0,0 +1,18 @@
+/* { dg-options "-Ofast -mlow-precision-div" } */
+/* { dg-do compile } */
+
+float
+f1 (float x, float y)
+{
+ return y / x;
+}
+
+/* { dg-final { scan-assembler {\tfrecpe\t(s[0-9]+), s0\n\tfrecps\t(s[0-9]+), \1, s0\n\tfmul\t\1, \1, s1\n\tfmul\ts0, \1, \2\n} } } */
+
+double
+f2 (double x, double y)
+{
+ return y / x;
+}
+
+/* { dg-final { scan-assembler {\tfrecpe\t(d[0-9]+), d0\n\tfrecps\t(d[0-9]+), \1, d0\n\tfmul\t\1, \1, \2\n\tfrecps\t\2, \1, d0\n\tfmul\t\1, \1, d1\n\tfmul\td0, \1, \2\n} } } */
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