re PR middle-end/19068 ([3.3 only] Wrong code for MIN_EXPR and MAX_EXPR)

	PR middle-end/19068
	* expr.c (expand_expr_real_1) <MAX_EXPR>: Ensure that target, op0
	and op1 are all registers (or constants) before expanding the RTL
	comparison sequence [to avoid reg_overlap_mentioned (target, op1)].

	* g++.dg/opt/max1.C: New test case.

From-SVN: r92404

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 8151e64a93c098051bcc5c81ae684bc3f1c453b5..28cbd426ba616aa3453cdaba4f5c3440b781f61a 100644 (file)
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,10 @@
+2004-12-19  Roger Sayle  <roger@eyesopen.com>
+
+       PR middle-end/19068
+       * expr.c (expand_expr_real_1) <MAX_EXPR>: Ensure that target, op0
+       and op1 are all registers (or constants) before expanding the RTL
+       comparison sequence [to avoid reg_overlap_mentioned (target, op1)].
+
 2004-12-16  Eric Botcazou  <ebotcazou@adacore.com>
 
        PR middle-end/18882

diff --git a/gcc/expr.c b/gcc/expr.c
index a2b0c830568713ce40f4674ec0ebab6fb61eb239..78b35db8c8470ca4352b92e4e62910609b4ce786 100644 (file)
--- a/gcc/expr.c
+++ b/gcc/expr.c
@@ -8462,9 +8462,14 @@ expand_expr (exp, target, tmode, modifier)
       /* At this point, a MEM target is no longer useful; we will get better
         code without it.  */
 
-      if (GET_CODE (target) == MEM)
+      if (! REG_P (target))
        target = gen_reg_rtx (mode);
 
+      /* We generate better code and avoid problems with op1 mentioning
+        target by forcing op1 into a pseudo if it isn't a constant.  */
+      if (! CONSTANT_P (op1))
+       op1 = force_reg (mode, op1);
+
       if (target != op0)
        emit_move_insn (target, op0);
 

diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index e1d6b270823c3f6ab16e48ea39bcabbabf8bf46c..383a8e6082a44c8e754374eedb91b2b84485f41c 100644 (file)
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,8 @@
+2004-12-19  Roger Sayle  <roger@eyesopen.com>
+
+       PR middle-end/19068
+       * g++.dg/opt/max1.C: New test case.
+
 2004-12-16  Wolfgang Bangerth  <bangerth@dealii.com>
 
        * g++.dg/other/complex1.C: New test.