From b1896e61038b3c63b567393ba12ddaa99f6f4a43 Mon Sep 17 00:00:00 2001
From: Mark Mitchell <mark@codesourcery.com>
Date: Sat, 6 Apr 2002 19:42:22 +0000
Subject: [PATCH] re PR rtl-optimization/5120 (tail recursion incorrect using
-O2)
PR opt/5120
* sibcall.c (optimize_sibling_and_tail_recursive_call): Clear
RTX_UNCHANGING_P for the functions arguments when a tail call
is made.
From-SVN: r51969
---
gcc/ChangeLog | 7 +
gcc/sibcall.c | 12 ++
gcc/testsuite/ChangeLog | 5 +
.../gcc.c-torture/execute/20020406-1.c | 123 ++++++++++++++++++
4 files changed, 147 insertions(+)
create mode 100644 gcc/testsuite/gcc.c-torture/execute/20020406-1.c
diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 6c451f949abc..548caa9c81f7 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,10 @@
+2002-04-06 Mark Mitchell <mark@codesourcery.com>
+
+ PR opt/5120
+ * sibcall.c (optimize_sibling_and_tail_recursive_call): Clear
+ RTX_UNCHANGING_P for the functions arguments when a tail call
+ is made.
+
2002-04-06 Jason Merrill <jason@redhat.com>
* toplev.c (flag_no_inline, flag_really_no_inline): Default to 2.
diff --git a/gcc/sibcall.c b/gcc/sibcall.c
index 5a7997cb0387..6e753fa2fa99 100644
--- a/gcc/sibcall.c
+++ b/gcc/sibcall.c
@@ -31,6 +31,7 @@ Software Foundation, 59 Temple Place - Suite 330, Boston, MA
#include "basic-block.h"
#include "output.h"
#include "except.h"
+#include "tree.h"
/* In case alternate_exit_block contains copy from pseudo, to return value,
record the pseudo here. In such case the pseudo must be set to function
@@ -730,6 +731,7 @@ optimize_sibling_and_tail_recursive_calls ()
if (successful_sibling_call)
{
rtx insn;
+ tree arg;
/* A sibling call sequence invalidates any REG_EQUIV notes made for
this function's incoming arguments.
@@ -754,6 +756,16 @@ optimize_sibling_and_tail_recursive_calls ()
if (INSN_P (insn))
purge_mem_unchanging_flag (PATTERN (insn));
}
+
+ /* Similarly, invalidate RTX_UNCHANGING_P for any incoming
+ arguments passed in registers. */
+ for (arg = DECL_ARGUMENTS (current_function_decl);
+ arg;
+ arg = TREE_CHAIN (arg))
+ {
+ if (REG_P (DECL_RTL (arg)))
+ RTX_UNCHANGING_P (DECL_RTL (arg)) = false;
+ }
}
/* There may have been NOTE_INSN_BLOCK_{BEGIN,END} notes in the
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 7b92bce96e6d..ddd75d41ea88 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,8 @@
+2002-04-06 Mark Mitchell <mark@codesourcery.com>
+
+ PR c/5120
+ * gcc.dg/20020406-1.c: New test.
+
2002-04-04 David S. Miller <davem@redhat.com>
* gcc.c-torture/execute/20020404-1.c: New test.
diff --git a/gcc/testsuite/gcc.c-torture/execute/20020406-1.c b/gcc/testsuite/gcc.c-torture/execute/20020406-1.c
new file mode 100644
index 000000000000..6d4967eae55c
--- /dev/null
+++ b/gcc/testsuite/gcc.c-torture/execute/20020406-1.c
@@ -0,0 +1,123 @@
+// Origin: abbott@dima.unige.it
+// PR c/5120
+
+typedef unsigned int FFelem;
+
+FFelem FFmul(const FFelem x, const FFelem y)
+{
+ return x;
+}
+
+
+struct DUPFFstruct
+{
+ int maxdeg;
+ int deg;
+ FFelem *coeffs;
+};
+
+typedef struct DUPFFstruct *DUPFF;
+
+
+int DUPFFdeg(const DUPFF f)
+{
+ return f->deg;
+}
+
+
+DUPFF DUPFFnew(const int maxdeg)
+{
+ DUPFF ans = (DUPFF)malloc(sizeof(struct DUPFFstruct));
+ ans->coeffs = 0;
+ if (maxdeg >= 0) ans->coeffs = (FFelem*)malloc((maxdeg+1)*sizeof(FFelem));
+ ans->maxdeg = maxdeg;
+ ans->deg = -1;
+ return ans;
+}
+
+void DUPFFfree(DUPFF x)
+{
+}
+
+void DUPFFswap(DUPFF x, DUPFF y)
+{
+}
+
+
+DUPFF DUPFFcopy(const DUPFF x)
+{
+ return x;
+}
+
+
+void DUPFFshift_add(DUPFF f, const DUPFF g, int deg, const FFelem coeff)
+{
+}
+
+
+DUPFF DUPFFexgcd(DUPFF *fcofac, DUPFF *gcofac, const DUPFF f, const DUPFF g)
+{
+ DUPFF u, v, uf, ug, vf, vg;
+ FFelem q, lcu, lcvrecip, p;
+ int df, dg, du, dv;
+
+ printf("DUPFFexgcd called on degrees %d and %d\n", DUPFFdeg(f), DUPFFdeg(g));
+ if (DUPFFdeg(f) < DUPFFdeg(g)) return DUPFFexgcd(gcofac, fcofac, g, f); /*** BUG IN THIS LINE ***/
+ if (DUPFFdeg(f) != 2 || DUPFFdeg(g) != 1) abort();
+ if (f->coeffs[0] == 0) return f;
+ /****** NEVER REACH HERE IN THE EXAMPLE ******/
+ p = 2;
+
+ df = DUPFFdeg(f); if (df < 0) df = 0; /* both inputs are zero */
+ dg = DUPFFdeg(g); if (dg < 0) dg = 0; /* one input is zero */
+ u = DUPFFcopy(f);
+ v = DUPFFcopy(g);
+
+ uf = DUPFFnew(dg); uf->coeffs[0] = 1; uf->deg = 0;
+ ug = DUPFFnew(df);
+ vf = DUPFFnew(dg);
+ vg = DUPFFnew(df); vg->coeffs[0] = 1; vg->deg = 0;
+
+ while (DUPFFdeg(v) > 0)
+ {
+ dv = DUPFFdeg(v);
+ lcvrecip = FFmul(1, v->coeffs[dv]);
+ while (DUPFFdeg(u) >= dv)
+ {
+ du = DUPFFdeg(u);
+ lcu = u->coeffs[du];
+ q = FFmul(lcu, lcvrecip);
+ DUPFFshift_add(u, v, du-dv, p-q);
+ DUPFFshift_add(uf, vf, du-dv, p-q);
+ DUPFFshift_add(ug, vg, du-dv, p-q);
+ }
+ DUPFFswap(u, v);
+ DUPFFswap(uf, vf);
+ DUPFFswap(ug, vg);
+ }
+ if (DUPFFdeg(v) == 0)
+ {
+ DUPFFswap(u, v);
+ DUPFFswap(uf, vf);
+ DUPFFswap(ug, vg);
+ }
+ DUPFFfree(vf);
+ DUPFFfree(vg);
+ DUPFFfree(v);
+ *fcofac = uf;
+ *gcofac = ug;
+ return u;
+}
+
+
+
+int main()
+{
+ DUPFF f, g, cf, cg, h;
+ f = DUPFFnew(1); f->coeffs[1] = 1; f->deg = 1;
+ g = DUPFFnew(2); g->coeffs[2] = 1; g->deg = 2;
+
+ printf("calling DUPFFexgcd on degrees %d and %d\n", DUPFFdeg(f), DUPFFdeg(g)) ;
+ h = DUPFFexgcd(&cf, &cg, f, g);
+ return 0;
+}
--
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