aarch64: Tweak old vect-* tests to avoid new FAILs

I'm not sure what these test were originally designed to test.
vaddv and vmaxv seem to be testing for vectorisation, with associated
scan-assembler tests.  But they use arm_neon.h functions to test
the results, which would presumably also trip many of the scans.
That was probably what the split into vect-fmax-fmin.c and
vect-fmaxv-fminv-compile.c was supposed to avoid.

Anyway, the tests started failing after the recent change to allow
staged reductions for epilogue loops.  And epilogues came into play
because the reduction loops iterate LANES-1 rather than LANES times.
(vmaxv was trying to iterate LANES times, but the gimple optimisers
outsmarted it.  The other two explicitly had a count of LANES-1.)

Just suppressing epilogues causes other issues for vaddv and vmaxv.
The easiest fix therefore seemed to be to use an asm to hide the
initial value of the vmaxv loop (so that it really does iterate
LANES times) and then make the others match that style.

gcc/testsuite/
	PR testsuite/101506
	* gcc.target/aarch64/vect-vmaxv.c: Use an asm to hide the
	true initial value of the reduction from the vectorizer.
	* gcc.target/aarch64/vect-vaddv.c: Likewise.  Make the vector
	loop operate on exactly LANES (rather than LANES-1) iterations.
	* gcc.target/aarch64/vect-fmaxv-fminv.x: Likewise.

diff --git a/gcc/testsuite/gcc.target/aarch64/vect-fmaxv-fminv.x b/gcc/testsuite/gcc.target/aarch64/vect-fmaxv-fminv.x
index 0bc6ba494cf76e606a7084d74e71f629c4bb01a9..d3ba31c425a90bef4518b934fde7fb19ace47019 100644 (file)
--- a/gcc/testsuite/gcc.target/aarch64/vect-fmaxv-fminv.x
+++ b/gcc/testsuite/gcc.target/aarch64/vect-fmaxv-fminv.x
@@ -5,8 +5,9 @@ typedef double *__restrict__ pRF64;
 float maxv_f32 (pRF32 a)
 {
   int i;
-  float s = a[0];
-  for (i=1;i<8;i++)
+  float s;
+  asm ("" : "=w" (s) : "0" (a[0]));
+  for (i=0;i<8;i++)
     s = (s > a[i] ? s :  a[i]);
 
   return s;
@@ -15,8 +16,9 @@ float maxv_f32 (pRF32 a)
 float minv_f32 (pRF32 a)
 {
   int i;
-  float s = a[0];
-  for (i=1;i<16;i++)
+  float s;
+  asm ("" : "=w" (s) : "0" (a[0]));
+  for (i=0;i<16;i++)
     s = (s < a[i] ? s :  a[i]);
 
   return s;
@@ -25,8 +27,9 @@ float minv_f32 (pRF32 a)
 double maxv_f64 (pRF64 a)
 {
   int i;
-  double s = a[0];
-  for (i=1;i<8;i++)
+  double s;
+  asm ("" : "=w" (s) : "0" (a[0]));
+  for (i=0;i<8;i++)
     s = (s > a[i] ? s :  a[i]);
 
   return s;
@@ -35,8 +38,9 @@ double maxv_f64 (pRF64 a)
 double minv_f64 (pRF64 a)
 {
   int i;
-  double s = a[0];
-  for (i=1;i<16;i++)
+  double s;
+  asm ("" : "=w" (s) : "0" (a[0]));
+  for (i=0;i<16;i++)
     s = (s < a[i] ? s :  a[i]);
 
   return s;

diff --git a/gcc/testsuite/gcc.target/aarch64/vect-vaddv.c b/gcc/testsuite/gcc.target/aarch64/vect-vaddv.c
index 41e9157dbecf43e445ec6c7ec84221770485582b..3a12ae9706afa99fbf861078b337cf234ff2c1f8 100644 (file)
--- a/gcc/testsuite/gcc.target/aarch64/vect-vaddv.c
+++ b/gcc/testsuite/gcc.target/aarch64/vect-vaddv.c
@@ -57,8 +57,8 @@ test_vaddv##SUFFIX##_##TYPE##x##LANES##_t (void)                      \
   /* Calculate linearly.  */                                           \
   for (i = 0; i < moves; i++)                                          \
     {                                                                  \
-      out_l[i] = input_##TYPE[i];                                      \
-      for (j = 1; j < LANES; j++)                                      \
+      asm ("" : "=r" (out_l[i]) : "0" (0));                            \
+      for (j = 0; j < LANES; j++)                                      \
        out_l[i] += input_##TYPE[i + j];                                \
     }                                                                  \
                                                                        \

diff --git a/gcc/testsuite/gcc.target/aarch64/vect-vmaxv.c b/gcc/testsuite/gcc.target/aarch64/vect-vmaxv.c
index 4280834ec4a7de5d6f880affa95ebbabd45ebb39..1bdea890d3e2b96c7137f271ece983ce6faf51e2 100644 (file)
--- a/gcc/testsuite/gcc.target/aarch64/vect-vmaxv.c
+++ b/gcc/testsuite/gcc.target/aarch64/vect-vmaxv.c
@@ -36,7 +36,7 @@ test_v##MAXMIN##v##SUFFIX##_##TYPE##x##LANES##_t (void)                       \
   /* Calculate linearly.  */                                           \
   for (i = 0; i < moves; i++)                                          \
     {                                                                  \
-      out_l[i] = input_##TYPE[i];                                      \
+      asm ("" : "=r" (out_l[i]) : "0" (input_##TYPE[i]));              \
       for (j = 0; j < LANES; j++)                                      \
        out_l[i] = input_##TYPE[i + j] CMP_OP out_l[i]  ?               \
          input_##TYPE[i + j] : out_l[i];                               \