i386: Fix -mavx -mno-mavx2 ICE with VEC_COND_EXPR [PR93637]

As mentioned in the PR, for -mavx -mno-avx2 the backend does support
vcondv4div4df and vcondv8siv8sf optabs (while generally 32-byte vectors
aren't much supported in that case, it is performed using
vandps/vandnps/vorps).  The problem is that after the last generic vector
lowering (where the VEC_COND_EXPR still compares two V4DF vectors and
has two V4DI last operands and V4DI result and so is considered ok) fre4
folds the condition into constant, at which point the middle-end during
expansion will try vcond_mask_optab and fall back to trying to expand it
as the constant vector < 0 vcondv4div4di, but neither of them is supported
for -mavx -mno-avx2 and thus we ICE.

So, the options I see is either what the following patch does, also support
vcond_mask_v4div4di and vcond_mask_v4siv4si already for TARGET_AVX, or
require for vcondv4div4df and vcondv8siv8sf TARGET_AVX2 rather than current
TARGET_AVX.

2020-02-10  Jakub Jelinek  <jakub@redhat.com>

	PR target/93637
	* config/i386/sse.md (VI_256_AVX2): New mode iterator.
	(vcond_mask_<mode><sseintvecmodelower>): Use it instead of VI_256.
	Change condition from TARGET_AVX2 to TARGET_AVX.

	* gcc.target/i386/avx-pr93637.c: New test.

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 72c8ee6bd67744577a9d559ad12fcf6609334110..34091354380cff1b74778e8a11e6fcf3e80fddd7 100644 (file)
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,6 +1,13 @@
 2020-02-13  Jakub Jelinek  <jakub@redhat.com>
 
        Backported from mainline
+       2020-02-10  Jakub Jelinek  <jakub@redhat.com>
+
+       PR target/93637
+       * config/i386/sse.md (VI_256_AVX2): New mode iterator.
+       (vcond_mask_<mode><sseintvecmodelower>): Use it instead of VI_256.
+       Change condition from TARGET_AVX2 to TARGET_AVX.
+
        2020-02-08  Uroš Bizjak  <ubizjak@gmail.com>
                    Jakub Jelinek  <jakub@redhat.com>
 

diff --git a/gcc/config/i386/sse.md b/gcc/config/i386/sse.md
index 659cbff22f37ee1e92d292a9f4440a7ef05374a2..c0fe0eefd50dafbfcb3ca6bba20a933ad798fc24 100644 (file)
--- a/gcc/config/i386/sse.md
+++ b/gcc/config/i386/sse.md
@@ -3180,13 +3180,19 @@
          (match_operand:<avx512fmaskmode> 3 "register_operand")))]
   "TARGET_AVX512BW")
 
+;; As vcondv4div4df and vcondv8siv8sf are enabled already with TARGET_AVX,
+;; and their condition can be folded late into a constant, we need to
+;; support vcond_mask_v4div4di and vcond_mask_v8siv8si for TARGET_AVX.
+(define_mode_iterator VI_256_AVX2 [(V32QI "TARGET_AVX2") (V16HI "TARGET_AVX2")
+                                  V8SI V4DI])
+
 (define_expand "vcond_mask_<mode><sseintvecmodelower>"
-  [(set (match_operand:VI_256 0 "register_operand")
-       (vec_merge:VI_256
-         (match_operand:VI_256 1 "nonimmediate_operand")
-         (match_operand:VI_256 2 "nonimm_or_0_operand")
+  [(set (match_operand:VI_256_AVX2 0 "register_operand")
+       (vec_merge:VI_256_AVX2
+         (match_operand:VI_256_AVX2 1 "nonimmediate_operand")
+         (match_operand:VI_256_AVX2 2 "nonimm_or_0_operand")
          (match_operand:<sseintvecmode> 3 "register_operand")))]
-  "TARGET_AVX2"
+  "TARGET_AVX"
 {
   ix86_expand_sse_movcc (operands[0], operands[3],
                         operands[1], operands[2]);

diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index c7b8e6a585ae01a409da7bddb128a1e2f7fa4753..9ec4d50dac37edcf689d00f6e76616342c73199d 100644 (file)
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,6 +1,11 @@
 2020-02-13  Jakub Jelinek  <jakub@redhat.com>
 
        Backported from mainline
+       2020-02-10  Jakub Jelinek  <jakub@redhat.com>
+
+       PR target/93637
+       * gcc.target/i386/avx-pr93637.c: New test.
+
        2020-02-08  Uroš Bizjak  <ubizjak@gmail.com>
                    Jakub Jelinek  <jakub@redhat.com>
 

diff --git a/gcc/testsuite/gcc.target/i386/avx-pr93637.c b/gcc/testsuite/gcc.target/i386/avx-pr93637.c
new file mode 100644 (file)
index 0000000..9e7a0a7
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/avx-pr93637.c
@@ -0,0 +1,17 @@
+/* PR target/93637 */
+/* { dg-do compile } */
+/* { dg-options "-mavx -mno-avx2 -O3 --param sccvn-max-alias-queries-per-access=3" } */
+
+double
+foo (void)
+{
+  int i;
+  double r = 7.0;
+  double a[] = { 0.0, 0.0, -0.0, 0.0, 0.0, -0.0, 1.0, 0.0, 0.0, -0.0, 1.0, 0.0, 1.0, 1.0 };
+
+  for (i = 0; i < sizeof (a) / sizeof (a[0]); ++i)
+    if (a[i] == 0.0)
+      r = a[i];
+
+  return r;
+}