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-rw-r--r--lib/builtins/arm/aeabi_cfcmp.S91
1 files changed, 91 insertions, 0 deletions
diff --git a/lib/builtins/arm/aeabi_cfcmp.S b/lib/builtins/arm/aeabi_cfcmp.S
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+//===-- aeabi_cfcmp.S - EABI cfcmp* implementation ------------------------===//
+//
+// The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#include "../assembly.h"
+
+#if __BYTE_ORDER__ != __ORDER_LITTLE_ENDIAN__
+#error big endian support not implemented
+#endif
+
+#define APSR_Z (1 << 30)
+#define APSR_C (1 << 29)
+
+// void __aeabi_cfcmpeq(float a, float b) {
+// if (isnan(a) || isnan(b)) {
+// Z = 0; C = 1;
+// } else {
+// __aeabi_cfcmple(a, b);
+// }
+// }
+
+ .syntax unified
+ .p2align 2
+DEFINE_COMPILERRT_FUNCTION(__aeabi_cfcmpeq)
+ push {r0-r3, lr}
+ bl __aeabi_cfcmpeq_check_nan
+ cmp r0, #1
+ pop {r0-r3, lr}
+
+ // NaN has been ruled out, so __aeabi_cfcmple can't trap
+ bne __aeabi_cfcmple
+
+ msr CPSR_f, #APSR_C
+ JMP(lr)
+END_COMPILERRT_FUNCTION(__aeabi_cfcmpeq)
+
+
+// void __aeabi_cfcmple(float a, float b) {
+// if (__aeabi_fcmplt(a, b)) {
+// Z = 0; C = 0;
+// } else if (__aeabi_fcmpeq(a, b)) {
+// Z = 1; C = 1;
+// } else {
+// Z = 0; C = 1;
+// }
+// }
+
+ .syntax unified
+ .p2align 2
+DEFINE_COMPILERRT_FUNCTION(__aeabi_cfcmple)
+ // Per the RTABI, this function must preserve r0-r11.
+ // Save lr in the same instruction for compactness
+ push {r0-r3, lr}
+
+ bl __aeabi_fcmplt
+ cmp r0, #1
+ moveq ip, #0
+ beq 1f
+
+ ldm sp, {r0-r3}
+ bl __aeabi_fcmpeq
+ cmp r0, #1
+ moveq ip, #(APSR_C | APSR_Z)
+ movne ip, #(APSR_C)
+
+1:
+ msr CPSR_f, ip
+ pop {r0-r3}
+ POP_PC()
+END_COMPILERRT_FUNCTION(__aeabi_cfcmple)
+
+// int __aeabi_cfrcmple(float a, float b) {
+// return __aeabi_cfcmple(b, a);
+// }
+
+ .syntax unified
+ .p2align 2
+DEFINE_COMPILERRT_FUNCTION(__aeabi_cfrcmple)
+ // Swap r0 and r1
+ mov ip, r0
+ mov r0, r1
+ mov r1, ip
+
+ b __aeabi_cfcmple
+END_COMPILERRT_FUNCTION(__aeabi_cfrcmple)
+