Like https://gcc.gnu.org/ml/gcc-patches/2010-09/msg00060.html for
PowerPC, we should do something similar for aarch64. This pattern
does show up in SPEC CPU 2006 in astar but I did not look into
performance improvement of it though.
OK? Bootstrapped and tested on aarch64-linux-gnu with no regressions.
Thanks,
Andrew Pinski
ChangeLog:
* config/aarch64/aarch64.md (*frintz): New pattern.
testsuite/ChangeLog:
* testsuite/gcc.target/aarch64/floattointtofloat-1.c: New testcase.
commit 9cef5e196729df5a197b81b72192d687683a057a
Author: Andrew Pinski <apin...@cavium.com>
Date: Thu Aug 17 22:31:15 2017 -0700
Fix 19869: (double)(long)double_var could be better optimized
Use FRINTZ to optimize this.
Signed-off-by: Andrew Pinski <apin...@cavium.com>
diff --git a/gcc/config/aarch64/aarch64.md b/gcc/config/aarch64/aarch64.md
index 5e6b027..1439bd0 100644
--- a/gcc/config/aarch64/aarch64.md
+++ b/gcc/config/aarch64/aarch64.md
@@ -4645,6 +4645,16 @@
[(set_attr "type" "f_cvti2f")]
)
+(define_insn "*frintz"
+ [(set (match_operand:GPF 0 "register_operand" "=w")
+ (float:GPF (fix:GPI (match_operand:GPF 1 "register_operand" "w"))))]
+ "TARGET_FLOAT && flag_unsafe_math_optimizations && !flag_trapping_math"
+ "frintz %<GPF:s>0, %<GPF:s>1"
+ [(set_attr "simd" "yes")
+ (set_attr "fp" "no")
+ (set_attr "type" "neon_int_to_fp_<Vetype>")]
+)
+
;; If we do not have ARMv8.2-A 16-bit floating point extensions, the
;; midend will arrange for an SImode conversion to HFmode to first go
;; through DFmode, then to HFmode. But first it will try converting
diff --git a/gcc/testsuite/gcc.target/aarch64/floattointtofloat-1.c
b/gcc/testsuite/gcc.target/aarch64/floattointtofloat-1.c
new file mode 100644
index 0000000..c1209c6
--- /dev/null
+++ b/gcc/testsuite/gcc.target/aarch64/floattointtofloat-1.c
@@ -0,0 +1,20 @@
+/* { dg-do compile } */
+/* { dg-options "-Ofast" } */
+double dll(double a)
+{
+ return (long long)a;
+}
+double di(double a)
+{
+ return (int)a;
+}
+float fll(float a)
+{
+ return (long long)a;
+}
+float fi(float a)
+{
+ return (int)a;
+}
+/* { dg-final { scan-assembler-times "frintz" 4 } } */
+
