From e006ced29a861befefecbb9acb828a5ce8289a34 Mon Sep 17 00:00:00 2001
From: Falk Hueffner <falk@debian.org>
Date: Mon, 20 Oct 2003 09:59:45 +0200
Subject: [PATCH] re PR target/12654 (Incorrect comparison code generated for
Alpha)
PR target/12654
* config/alpha/alpha.c (alpha_emit_conditional_branch): Don't do
comparison against constant by adjusting the argument except for
EQ and NE.
From-SVN: r72696
---
gcc/ChangeLog | 7 ++++++
gcc/config/alpha/alpha.c | 8 +++----
.../gcc.c-torture/execute/20031020-1.c | 23 +++++++++++++++++++
3 files changed, 34 insertions(+), 4 deletions(-)
create mode 100644 gcc/testsuite/gcc.c-torture/execute/20031020-1.c
diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 4ebb882cc77e..20a8abcfc97e 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,10 @@
+2003-10-20 Falk Hueffner <falk@debian.org>
+
+ PR target/12654
+ * config/alpha/alpha.c (alpha_emit_conditional_branch): Don't do
+ comparison against constant by adjusting the argument except for
+ EQ and NE.
+
2003-10-19 Mark Mitchell <mark@codesourcery.com>
* config.gcc: Add support for arm926ejs, arm1026ejs, arm1136js,
diff --git a/gcc/config/alpha/alpha.c b/gcc/config/alpha/alpha.c
index c79a0b5799ed..69d996a17cb0 100644
--- a/gcc/config/alpha/alpha.c
+++ b/gcc/config/alpha/alpha.c
@@ -3160,10 +3160,10 @@ alpha_emit_conditional_branch (enum rtx_code code)
if (op1 == const0_rtx)
cmp_code = NIL, branch_code = code;
- /* We want to use cmpcc/bcc when we can, since there is a zero delay
- bypass between logicals and br/cmov on EV5. But we don't want to
- force valid immediate constants into registers needlessly. */
- else if (GET_CODE (op1) == CONST_INT)
+ /* If the constants doesn't fit into an immediate, but can
+ be generated by lda/ldah, we adjust the argument and
+ compare against zero, so we can use beq/bne directly. */
+ else if (GET_CODE (op1) == CONST_INT && (code == EQ || code == NE))
{
HOST_WIDE_INT v = INTVAL (op1), n = -v;
diff --git a/gcc/testsuite/gcc.c-torture/execute/20031020-1.c b/gcc/testsuite/gcc.c-torture/execute/20031020-1.c
new file mode 100644
index 000000000000..526ca0402f91
--- /dev/null
+++ b/gcc/testsuite/gcc.c-torture/execute/20031020-1.c
@@ -0,0 +1,23 @@
+/* PR target/12654
+ The Alpha backend tried to do a >= 1024 as (a - 1024) >= 0, which fails
+ for very large negative values. */
+/* Origin: tg@swox.com */
+
+#include <limits.h>
+
+extern void abort (void);
+
+void __attribute__((noinline))
+foo (long x)
+{
+ if (x >= 1024)
+ abort ();
+}
+
+int
+main ()
+{
+ foo (LONG_MIN);
+ foo (LONG_MIN + 10000);
+ return 0;
+}
--
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