This patch fixes PR target/110083, an ICE-on-valid regression exposed by
my recent PTEST improvements (to address PR target/109973). The latent
bug (admittedly mine) is that the scalar-to-vector (STV) pass doesn't update
or delete REG_EQUAL notes attached to COMPARE instructions. As a result
the operands of COMPARE would be mismatched, with the register transformed
to V1TImode, but the immediate operand left as const_wide_int, which is
valid for TImode but not V1TImode. This remained latent when the STV
conversion converted the mode of the COMPARE to CCmode, with later passes
recognizing the REG_EQUAL note is obviously invalid as the modes didn't
match, but now that we (correctly) preserve the CCZmode on COMPARE, the
mismatched operand modes trigger a sanity checking ICE downstream.
Fixed by updating (or deleting) any REG_EQUAL notes in convert_compare.
Before:
(expr_list:REG_EQUAL (compare:CCZ (reg:V1TI 119 [ ivin.29_38 ])
(const_wide_int 0x80000000000000000000000000000000))
After:
(expr_list:REG_EQUAL (compare:CCZ (reg:V1TI 119 [ ivin.29_38 ])
(const_vector:V1TI [
(const_wide_int 0x80000000000000000000000000000000)
]))
This patch has been tested on x86_64-pc-linux-gnu with make bootstrap
and make -k check, both with and without --target_board=unix{-m32}
with no new failures. Ok for mainline?
2023-06-03 Roger Sayle <ro...@nextmovesoftware.com>
gcc/ChangeLog
PR target/110083
* config/i386/i386-features.cc (scalar_chain::convert_compare):
Update or delete REG_EQUAL notes, converting CONST_INT and
CONST_WIDE_INT immediate operands to a suitable CONST_VECTOR.
gcc/testsuite/ChangeLog
PR target/110083
* gcc.target/i386/pr110083.c: New test case.
Roger
--
diff --git a/gcc/config/i386/i386-features.cc b/gcc/config/i386/i386-features.cc
index 3417f6b..4a3b07a 100644
--- a/gcc/config/i386/i386-features.cc
+++ b/gcc/config/i386/i386-features.cc
@@ -980,6 +980,39 @@ rtx
scalar_chain::convert_compare (rtx op1, rtx op2, rtx_insn *insn)
{
rtx src, tmp;
+
+ /* Handle any REG_EQUAL notes. */
+ tmp = find_reg_equal_equiv_note (insn);
+ if (tmp)
+ {
+ if (GET_CODE (XEXP (tmp, 0)) == COMPARE
+ && GET_MODE (XEXP (tmp, 0)) == CCZmode
+ && REG_P (XEXP (XEXP (tmp, 0), 0)))
+ {
+ rtx *op = &XEXP (XEXP (tmp, 0), 1);
+ if (CONST_SCALAR_INT_P (*op))
+ {
+ if (constm1_operand (*op, GET_MODE (*op)))
+ *op = CONSTM1_RTX (vmode);
+ else
+ {
+ unsigned n = GET_MODE_NUNITS (vmode);
+ rtx *v = XALLOCAVEC (rtx, n);
+ v[0] = *op;
+ for (unsigned i = 1; i < n; ++i)
+ v[i] = const0_rtx;
+ *op = gen_rtx_CONST_VECTOR (vmode, gen_rtvec_v (n, v));
+ }
+ tmp = NULL_RTX;
+ }
+ else if (REG_P (*op))
+ tmp = NULL_RTX;
+ }
+
+ if (tmp)
+ remove_note (insn, tmp);
+ }
+
/* Comparison against anything other than zero, requires an XOR. */
if (op2 != const0_rtx)
{
diff --git a/gcc/testsuite/gcc.target/i386/pr110083.c
b/gcc/testsuite/gcc.target/i386/pr110083.c
new file mode 100644
index 0000000..4b38ca8
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/pr110083.c
@@ -0,0 +1,26 @@
+/* { dg-do compile { target int128 } } */
+/* { dg-options "-O2 -msse4 -mstv -mno-stackrealign" } */
+typedef int TItype __attribute__ ((mode (TI)));
+typedef unsigned int UTItype __attribute__ ((mode (TI)));
+
+void foo (void)
+{
+ static volatile TItype ivin, ivout;
+ static volatile float fv1, fv2;
+ ivin = ((TItype) (UTItype) ~ (((UTItype) ~ (UTItype) 0) >> 1));
+ fv1 = ((TItype) (UTItype) ~ (((UTItype) ~ (UTItype) 0) >> 1));
+ fv2 = ivin;
+ ivout = fv2;
+ if (ivin != ((TItype) (UTItype) ~ (((UTItype) ~ (UTItype) 0) >> 1))
+ || ((((128) > sizeof (TItype) * 8 - 1)) && ivout != ivin)
+ || ((((128) > sizeof (TItype) * 8 - 1))
+ && ivout !=
+ ((TItype) (UTItype) ~ (((UTItype) ~ (UTItype) 0) >> 1)))
+ || fv1 !=
+ (float) ((TItype) (UTItype) ~ (((UTItype) ~ (UTItype) 0) >> 1))
+ || fv2 !=
+ (float) ((TItype) (UTItype) ~ (((UTItype) ~ (UTItype) 0) >> 1))
+ || fv1 != fv2)
+ __builtin_abort ();
+}
+
