arm: Fix uaddvdi4 expander [PR93494]

uaddvdi4 expander has an optimization for the low 32-bits of the 2nd input
operand known to be 0.  Unfortunately, in that case it only emits copying of
the low 32 bits to the low 32 bits of the destination, but doesn't emit the
addition with overflow detection for the high 64 bits.
Well, to be precise, it emits it, but into an RTL sequence returned by
gen_uaddvsi4, but that sequence isn't emitted anywhere.

2020-01-30  Jakub Jelinek  <jakub@redhat.com>

	PR target/93494
	* config/arm/arm.md (uaddvdi4): Actually emit what gen_uaddvsi4
	returned.

	* gcc.c-torture/execute/pr93494.c: New test.

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 4beb639..a141e06 100644 (file)
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,5 +1,9 @@
 2020-01-30  Jakub Jelinek  <jakub@redhat.com>
 
+       PR target/93494
+       * config/arm/arm.md (uaddvdi4): Actually emit what gen_uaddvsi4
+       returned.
+
        PR target/91824
        * config/i386/sse.md
        (*<sse>_movmsk<ssemodesuffix><avxsizesuffix>_zext): Renamed to ...

diff --git a/gcc/config/arm/arm.md b/gcc/config/arm/arm.md
index 0454908..dd73263 100644 (file)
--- a/gcc/config/arm/arm.md
+++ b/gcc/config/arm/arm.md
@@ -721,7 +721,7 @@
       if (!arm_add_operand (hi_op2, SImode))
        hi_op2 = force_reg (SImode, hi_op2);
 
-      gen_uaddvsi4 (hi_result, hi_op1, hi_op2, operands[3]);
+      emit_insn (gen_uaddvsi4 (hi_result, hi_op1, hi_op2, operands[3]));
     }
   else
     {

diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 597788a..ab61b48 100644 (file)
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,8 @@
+2020-01-30  Jakub Jelinek  <jakub@redhat.com>
+
+       PR target/93494
+       * gcc.c-torture/execute/pr93494.c: New test.
+
 2020-01-30  Paolo Carlini  <paolo.carlini@oracle.com>
 
        PR c++/90338

diff --git a/gcc/testsuite/gcc.c-torture/execute/pr93494.c b/gcc/testsuite/gcc.c-torture/execute/pr93494.c
new file mode 100644 (file)
index 0000000..ef70403
--- /dev/null
+++ b/gcc/testsuite/gcc.c-torture/execute/pr93494.c
@@ -0,0 +1,13 @@
+/* PR target/93494 */
+
+unsigned short a;
+
+int
+main ()
+{
+  register unsigned long long y = 0;
+  int x = __builtin_add_overflow (y, 0ULL, &a);
+  if (x || a)
+    __builtin_abort ();
+  return 0;
+}