i386: Fix up __builtin_ia32_b{extr{,i}_u{32,64},zhi_{s,d}i} folding [PR116287]

The GENERIC folding of these builtins have cases where it folds to a
constant regardless of the value of the first operand.  If so, we need
to use omit_one_operand to avoid throwing away side-effects in the first
operand if any.  The cases which verify the first argument is INTEGER_CST
don't need that, INTEGER_CST doesn't have side-effects.

2024-08-09  Jakub Jelinek  <jakub@redhat.com>

	PR target/116287
	* config/i386/i386.cc (ix86_fold_builtin) <case IX86_BUILTIN_BEXTR32>:
	When folding into zero without checking whether first argument is
	constant, use omit_one_operand.
	(ix86_fold_builtin) <case IX86_BUILTIN_BZHI32>: Likewise.

	* gcc.target/i386/bmi-pr116287.c: New test.
	* gcc.target/i386/bmi2-pr116287.c: New test.
	* gcc.target/i386/tbm-pr116287.c: New test.

diff --git a/gcc/config/i386/i386.cc b/gcc/config/i386/i386.cc
index 02e282904410d5c9efbbcbb9693a84ad32ed670b..f044826269ca1f8224eca1fad57755d0b0b32ce4 100644 (file)
--- a/gcc/config/i386/i386.cc
+++ b/gcc/config/i386/i386.cc
@@ -18549,9 +18549,11 @@ ix86_fold_builtin (tree fndecl, int n_args,
              unsigned int prec = TYPE_PRECISION (TREE_TYPE (args[0]));
              unsigned int start = tree_to_uhwi (args[1]);
              unsigned int len = (start & 0xff00) >> 8;
+             tree lhs_type = TREE_TYPE (TREE_TYPE (fndecl));
              start &= 0xff;
              if (start >= prec || len == 0)
-               res = 0;
+               return omit_one_operand (lhs_type, build_zero_cst (lhs_type),
+                                        args[0]);
              else if (!tree_fits_uhwi_p (args[0]))
                break;
              else
@@ -18560,7 +18562,7 @@ ix86_fold_builtin (tree fndecl, int n_args,
                len = prec;
              if (len < HOST_BITS_PER_WIDE_INT)
                res &= (HOST_WIDE_INT_1U << len) - 1;
-             return build_int_cstu (TREE_TYPE (TREE_TYPE (fndecl)), res);
+             return build_int_cstu (lhs_type, res);
            }
          break;
 
@@ -18570,15 +18572,17 @@ ix86_fold_builtin (tree fndecl, int n_args,
          if (tree_fits_uhwi_p (args[1]))
            {
              unsigned int idx = tree_to_uhwi (args[1]) & 0xff;
+             tree lhs_type = TREE_TYPE (TREE_TYPE (fndecl));
              if (idx >= TYPE_PRECISION (TREE_TYPE (args[0])))
                return args[0];
              if (idx == 0)
-               return build_int_cst (TREE_TYPE (TREE_TYPE (fndecl)), 0);
+               return omit_one_operand (lhs_type, build_zero_cst (lhs_type),
+                                        args[0]);
              if (!tree_fits_uhwi_p (args[0]))
                break;
              unsigned HOST_WIDE_INT res = tree_to_uhwi (args[0]);
              res &= ~(HOST_WIDE_INT_M1U << idx);
-             return build_int_cstu (TREE_TYPE (TREE_TYPE (fndecl)), res);
+             return build_int_cstu (lhs_type, res);
            }
          break;
 

diff --git a/gcc/testsuite/gcc.target/i386/bmi-pr116287.c b/gcc/testsuite/gcc.target/i386/bmi-pr116287.c
new file mode 100644 (file)
index 0000000..2212cb4
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/bmi-pr116287.c
@@ -0,0 +1,28 @@
+/* PR target/116287 */
+/* { dg-do run { target bmi } } */
+/* { dg-options "-O2 -mbmi" } */
+
+#include <x86intrin.h>
+
+#include "bmi-check.h"
+
+static void
+bmi_test ()
+{
+  unsigned int a = 0;
+  if (__builtin_ia32_bextr_u32 (a++, 0) != 0)
+    abort ();
+  if (__builtin_ia32_bextr_u32 (a++, 0x120) != 0)
+    abort ();
+  if (a != 2)
+    abort ();
+#ifdef __x86_64__
+  unsigned long long b = 0;
+  if (__builtin_ia32_bextr_u64 (b++, 0) != 0)
+    abort ();
+  if (__builtin_ia32_bextr_u64 (b++, 0x140) != 0)
+    abort ();
+  if (b != 2)
+    abort ();
+#endif
+}

diff --git a/gcc/testsuite/gcc.target/i386/bmi2-pr116287.c b/gcc/testsuite/gcc.target/i386/bmi2-pr116287.c
new file mode 100644 (file)
index 0000000..51c939c
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/bmi2-pr116287.c
@@ -0,0 +1,24 @@
+/* PR target/116287 */
+/* { dg-do run { target bmi2 } } */
+/* { dg-options "-O2 -mbmi2" } */
+
+#include <x86intrin.h>
+
+#include "bmi2-check.h"
+
+static void
+bmi2_test ()
+{
+  unsigned int a = 0;
+  if (__builtin_ia32_bzhi_si (a++, 0) != 0)
+    abort ();
+  if (a != 1)
+    abort ();
+#ifdef __x86_64__
+  unsigned long long b = 0;
+  if (__builtin_ia32_bzhi_di (b++, 0) != 0)
+    abort ();
+  if (b != 1)
+    abort ();
+#endif
+}

diff --git a/gcc/testsuite/gcc.target/i386/tbm-pr116287.c b/gcc/testsuite/gcc.target/i386/tbm-pr116287.c
new file mode 100644 (file)
index 0000000..a229d8b
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/tbm-pr116287.c
@@ -0,0 +1,29 @@
+/* PR target/116287 */
+/* { dg-do compile } */
+/* { dg-options "-O2 -mtbm -fdump-tree-optimized" } */
+/* { dg-final { scan-tree-dump-not "link_error \\\(\\\);" "optimized" } } */
+
+#include <x86intrin.h>
+
+extern void link_error (void);
+
+void
+tbm_test ()
+{
+  unsigned int a = 0;
+  if (__builtin_ia32_bextri_u32 (a++, 0) != 0)
+    link_error ();
+  if (__builtin_ia32_bextri_u32 (a++, 0x120) != 0)
+    link_error ();
+  if (a != 2)
+    link_error ();
+#ifdef __x86_64__
+  unsigned long long b = 0;
+  if (__builtin_ia32_bextr_u64 (b++, 0) != 0)
+    link_error ();
+  if (__builtin_ia32_bextr_u64 (b++, 0x140) != 0)
+    link_error ();
+  if (b != 2)
+    link_error ();
+#endif
+}