[PATCH] PR target/69225: gcc uses double precision instead of single float with -m32 -std=c99 -msoft-float

["H.J. Lu" <hjl dot tools at gmail dot com>]

When FPU isn't used, there is no excess precision.  We should set
FLT_EVAL_METHOD to 0 if 387 is disabled.

OK for trunk?

Thanks.

H.J.
---
gcc/

	PR target/69225
	* config/i386/i386.h (TARGET_FLT_EVAL_METHOD): Set to 0 if
	TARGET_80387 is false.

gcc/testsuite

	PR target/69225
	* gcc.target/i386/pr69225-1.c: New test.
	* gcc.target/i386/pr69225-2.c: Likewise.
	* gcc.target/i386/pr69225-3.c: Likewise.
	* gcc.target/i386/pr69225-4.c: Likewise.
	* gcc.target/i386/pr69225-5.c: Likewise.
	* gcc.target/i386/pr69225-6.c: Likewise.
---
 gcc/config/i386/i386.h                    | 4 ++--
 gcc/testsuite/gcc.target/i386/pr69225-1.c | 8 ++++++++
 gcc/testsuite/gcc.target/i386/pr69225-2.c | 8 ++++++++
 gcc/testsuite/gcc.target/i386/pr69225-3.c | 8 ++++++++
 gcc/testsuite/gcc.target/i386/pr69225-4.c | 8 ++++++++
 gcc/testsuite/gcc.target/i386/pr69225-5.c | 8 ++++++++
 gcc/testsuite/gcc.target/i386/pr69225-6.c | 8 ++++++++
 7 files changed, 50 insertions(+), 2 deletions(-)
 create mode 100644 gcc/testsuite/gcc.target/i386/pr69225-1.c
 create mode 100644 gcc/testsuite/gcc.target/i386/pr69225-2.c
 create mode 100644 gcc/testsuite/gcc.target/i386/pr69225-3.c
 create mode 100644 gcc/testsuite/gcc.target/i386/pr69225-4.c
 create mode 100644 gcc/testsuite/gcc.target/i386/pr69225-5.c
 create mode 100644 gcc/testsuite/gcc.target/i386/pr69225-6.c

diff --git a/gcc/config/i386/i386.h b/gcc/config/i386/i386.h
index dcaa011..5c97fd1 100644
--- a/gcc/config/i386/i386.h
+++ b/gcc/config/i386/i386.h
@@ -692,9 +692,9 @@ extern const char *host_detect_local_cpu (int argc, const char **argv);
    FPU, assume that the fpcw is set to extended precision; when using
    only SSE, rounding is correct; when using both SSE and the FPU,
    the rounding precision is indeterminate, since either may be chosen
-   apparently at random.  */
+   apparently at random.  Also set to 0 if FPU isn't used.  */
 #define TARGET_FLT_EVAL_METHOD \
-  (TARGET_MIX_SSE_I387 ? -1 : TARGET_SSE_MATH ? 0 : 2)
+  (TARGET_MIX_SSE_I387 ? -1 : (TARGET_SSE_MATH || !TARGET_80387) ? 0 : 2)
 
 /* Whether to allow x87 floating-point arithmetic on MODE (one of
    SFmode, DFmode and XFmode) in the current excess precision
diff --git a/gcc/testsuite/gcc.target/i386/pr69225-1.c b/gcc/testsuite/gcc.target/i386/pr69225-1.c
new file mode 100644
index 0000000..cc5b782
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/pr69225-1.c
@@ -0,0 +1,8 @@
+/* { dg-do compile} */
+/* { dg-options "-msse2 -mfpmath=sse" } */
+
+#include <float.h>
+
+#if FLT_EVAL_METHOD != 0
+# error FLT_EVAL_METHOD != 0
+#endif
diff --git a/gcc/testsuite/gcc.target/i386/pr69225-2.c b/gcc/testsuite/gcc.target/i386/pr69225-2.c
new file mode 100644
index 0000000..cd0a626
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/pr69225-2.c
@@ -0,0 +1,8 @@
+/* { dg-do compile} */
+/* { dg-options "-mno-sse -mno-80387" } */
+
+#include <float.h>
+
+#if FLT_EVAL_METHOD != 0
+# error FLT_EVAL_METHOD != 0
+#endif
diff --git a/gcc/testsuite/gcc.target/i386/pr69225-3.c b/gcc/testsuite/gcc.target/i386/pr69225-3.c
new file mode 100644
index 0000000..1440b74
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/pr69225-3.c
@@ -0,0 +1,8 @@
+/* { dg-do compile} */
+/* { dg-options "-m80387 -mfpmath=387" } */
+
+#include <float.h>
+
+#if FLT_EVAL_METHOD != 2
+# error FLT_EVAL_METHOD != 2
+#endif
diff --git a/gcc/testsuite/gcc.target/i386/pr69225-4.c b/gcc/testsuite/gcc.target/i386/pr69225-4.c
new file mode 100644
index 0000000..b032a5f
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/pr69225-4.c
@@ -0,0 +1,8 @@
+/* { dg-do compile} */
+/* { dg-options "-msse2 -mfancy-math-387 -mfpmath=sse" } */
+
+#include <float.h>
+
+#if FLT_EVAL_METHOD != 0
+# error FLT_EVAL_METHOD != 0
+#endif
diff --git a/gcc/testsuite/gcc.target/i386/pr69225-5.c b/gcc/testsuite/gcc.target/i386/pr69225-5.c
new file mode 100644
index 0000000..4162f77
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/pr69225-5.c
@@ -0,0 +1,8 @@
+/* { dg-do compile} */
+/* { dg-options "-msse2 -m80387 -mfpmath=sse,387" } */
+
+#include <float.h>
+
+#if FLT_EVAL_METHOD != -1
+# error FLT_EVAL_METHOD != -1
+#endif
diff --git a/gcc/testsuite/gcc.target/i386/pr69225-6.c b/gcc/testsuite/gcc.target/i386/pr69225-6.c
new file mode 100644
index 0000000..cd5f419
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/pr69225-6.c
@@ -0,0 +1,8 @@
+/* { dg-do compile} */
+/* { dg-options "-mno-80387" } */
+
+#include <float.h>
+
+#if FLT_EVAL_METHOD != 0
+# error FLT_EVAL_METHOD != 0
+#endif
-- 
2.5.0