* [PATCH] Disallow paradoxical subregs when outer mode is SCALAR_FLOAT_MODE_P.
@ 2021-09-10 4:52 liuhongt
0 siblings, 0 replies; only message in thread
From: liuhongt @ 2021-09-10 4:52 UTC (permalink / raw)
To: gcc-patches; +Cc: richard.guenther, rdsandiford, crazylht
Hi:
In general_operand, paradoxical subregs w/ outermode SCALAR_FLOAT_MODE_P
are not allowed unless lra_in_progress, so this patch add the restriction
to validate_subreg as well.
Bootstrapped and regtested on x86_64-linux-gnu{-m32,}
Also the newly added tests are compiled with aarch64-linux-gnu-gcc w/o ICE.
Ok for trunk?
gcc/ChangeLog:
PR middle-end/102254
PR middle-end/102154
* emit-rtl.c (validate_subreg): Disallow paradoxical subregs
when omode is SCALAR_FLOAT_MODE_P.
gcc/testsuite/ChangeLog:
* gcc.target/i386/pr102254.c: New test.
---
gcc/emit-rtl.c | 8 ++++++--
gcc/testsuite/gcc.target/i386/pr102254.c | 23 +++++++++++++++++++++++
2 files changed, 29 insertions(+), 2 deletions(-)
create mode 100644 gcc/testsuite/gcc.target/i386/pr102254.c
diff --git a/gcc/emit-rtl.c b/gcc/emit-rtl.c
index 77ea8948ee8..29fa29e1001 100644
--- a/gcc/emit-rtl.c
+++ b/gcc/emit-rtl.c
@@ -922,9 +922,13 @@ validate_subreg (machine_mode omode, machine_mode imode,
poly_uint64 regsize = REGMODE_NATURAL_SIZE (imode);
- /* Paradoxical subregs must have offset zero. */
+ /* Paradoxical subregs must have offset zero and omode not
+ SCALAR_FLOAT_MODE_P.
+ i.e. things like (subreg:DF (reg:SF)) or (subreg:DF (reg:SI))
+ are not allowed. */
if (maybe_gt (osize, isize))
- return known_eq (offset, 0U);
+ return known_eq (offset, 0U)
+ && (!SCALAR_FLOAT_MODE_P (omode) || lra_in_progress);
/* This is a normal subreg. Verify that the offset is representable. */
diff --git a/gcc/testsuite/gcc.target/i386/pr102254.c b/gcc/testsuite/gcc.target/i386/pr102254.c
new file mode 100644
index 00000000000..93d25c3d317
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/pr102254.c
@@ -0,0 +1,23 @@
+/* { dg-do compile } */
+/* { dg-options "-Og" } */
+
+#define MODFL __builtin_modfl
+void
+foo (void)
+{
+ int x;
+ *((double *) &x) = 0;
+}
+
+void
+foo1 (void)
+{
+ float x;
+
+ *((double *) &x) = 0;
+}
+
+void foo2() {
+ long iptrll;
+ MODFL(0.5l, (long double *)&iptrll);
+}
--
2.27.0
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